Top 8 at the Legacy Challenge with Mono-White Initiative: In-Depth & Sideboard Guide

Lucas Giggs
05/02/2023 · 13 min read

Quick intro

Since the release of Commander Legends: Battle for Baldur's Gate, some cards have made a huge splash in Legacy , particularly Minsc & Boo, Timeless Heroes, and cards with the initiative.

From the latter, White Plume Adventurer and Seasoned Dungeoneer have totally revolutionized Monowhite, turning it into a deck that's both powerful and dangerous.

White Plume Adventurer
Seasoned Dungeoneer

The goal? To get these cards out in the early turns and snowball the initiative by venturing into the dungeon each round. It’s an awesome way to gain a huge edge on your opponent. 

Today, I'm gonna talk a bit about my current version of the deck that got me in the Top 8 of the last Legacy Challenge.

My current version of the deck

Mono White Initiative. Builder: LucasG1ggs.MTGO - Magic Online
Top8 in MTGO Legacy Challenge 32 #12515838 28-Jan-2023
Maindeck (60)
Creature [24]
4  Thalia, Guardian of Thraben   $1.79
2  Walking Ballista   $16.99
2  Palace Jailer   $2.29
4  Elite Spellbinder   $0.35
4  Solitude   $47.99
4  White Plume Adventurer   $5.99
4  Seasoned Dungeoneer   $7.49
Artifact [8]
4  Chrome Mox   $79.99
4  Lotus Petal   $9.49
Instant [4]
4  Swords to Plowshares   $0.99
Sorcery [4]
4  Emeria's Call   $11.99
Enchantment [3]
3  Touch the Spirit Realm   $0.59
Land [17]
1  Karakas   $32.99
4  City of Traitors   $379.99
4  Cavern of Souls   $64.99
4  Ancient Tomb   $89.99
2  Plains   $0.01
2  Eiganjo, Seat of the Empire   $9.99
Sideboard [15]
3  Empty-Shrine Kannushi   $0.59
4  Leyline of the Void   $10.99
2  Containment Priest   $0.35
2  Walking Ballista   $16.99
2  Archon of Absolution   $0.35
1  Cathar Commando   $0.69
1  Loran of the Third Path   $10.99
Buy this deck:

$373.95 Tix @cardhoarder   $9.35 / Week @cardhoarder   $998.34 @tcgplayer   $1,098.27 @cardkingdom  

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This deck doesn't differ much from one version to the next. The card base is the same: creatures with initiative, Sol Lands, Mox/Petals, Solitudes, and supporting cards that also help the deck’s plan, like Thalia, Elite Spellbinder and Palace Jailer.

Generally speaking, like I said, the plan is pretty straightforward: play a creature with initiative, use it to block our opponents creatures, and protect The Undercity  until it does the rest.

Card choices


Some versions use the Chancellor of the Annex to lock down opponent's first move and give them room to resolve their creatures, but I believe that overall, Thalia has much more impact in certain matches, like UR Delver and combo decks. She often serves as a lightning rod for removal, leaving the way paved for other creatures that can make a big board presence. But in a meta with more board-centric decks, she's not one of the best cards, so depending on what you expect to face, switching it can be a valid option.

Thalia, Guardian of Thraben
0.41 Tix


In addition to giving you the Initiative, it also turns you into The Monarch, which is also a hard ability to deal with for our opponents.

Palace Jailer
0.72 Tix

Even without any creatures in play, resolving a Palace Jailer on an empty board will give you card advantage each turn, and few decks can handle that easily. Remember, Palace Jailer's ability exiles the creature as long as you are the Monarch, so even if it gets removed, your opponent still has to 'steal the crown' to get the creature back ;) .


Ever since decks started fighting Initiative decks with cards with protection from white, Walking Ballista has become an essential card.

Walking Ballista
1.6 Tix

It's tough to steal the initiative from us and keep our creatures in check with removal and counters, but Ballista makes this even harder for our opponents. It ignores protection and it is also able to kill key cards like Delver of Secrets, Dragon's Rage Channeler, and Baleful Strix, plus it's also a powerful win condition on its own. It's almost essential to play with 4 of them in either your main deck or sideboard, and I'm fond of the configuration of 2 main deck + 2 sideboard.

Playing the deck: Mulliganing for Victory

Playing this deck isn't too hard, but it's not as simple as it looks. Basically, it's set up to make some unfair plays as early as turn one, whether it be playing Thalia to tax our opponent's spells, or Elite Spellbinder, to get key information about what and how to play in the following turns.

Elite Spellbinder
0.73 Tix

Beginning a game this way can be enough versus some archetypes, such as turn 1 Thalia vs. combo decks. But you must try to get a proactive and effective hand unless you know what you're up against.

In other words, mulliganing is essential with this type of deck and these are examples of hands you should avoid keeping 7, as the deck has potential to do much more effective things.

Example 1

This hand looks really tempting, since it can play a Thalia on turn 1, but aside from the Ballista, there are not many plays for the next turns. It's also tempting to play Solitude and blink it with Touch, but we don't have a white card to pitch and we also don't know the match-up, so it might not be so great. I have to admit that it's a close hand, but I personally would mulligan it.

Example 2

Having a hand with Cavern and Humans is usually good, but we only have action from turn 3. Of course, drawing a Sol land makes this hand incredible, being able to curve Seasoned Dungeoneer into Spellbinder, but we're not sure what our next draws will be so it could be a trap if we don't plan our game.

Example 3

This hand could also seem good - playing Spellbinder on turn 1 can give us some useful info to help us play our game, but the rest of the cards don't do much. Personally, I like to have a game plan that looks ahead to future turns, and this hand doesn't offer much for the future. With the deck's ability to make much better plays, I see this as an obvious mulligan too.

Matchups & Sideboard guide


Delver is always a dangerous deck. The best starting hands are the ones with Cavern of Souls to play around Force of Will and Daze. But we can't always afford to go after them, since even if we resolve a creature on turn 1, they still have the potential to steal the Initiative, with their flying creatures combined with removal, plus the ability to destroy our non-basic lands with Wasteland, slowing down our game. So if you get an opening hand that can make something relevant on turn 1, keep it.

After sideboarding, we bring in some extra Ballistas to tackle their early creatures and also to handle sideboard cards like Unchained Berserker. Hold these back for those creatures whenever you can, especially the Berserker, since the edge can quickly swing the other way.


It's an unfavorable matchup; he doesn't really care about our creatures, since assembling the combo gives them a quick victory, and even with the advantage that The Initiative gives us, they can win the game at any moment.

We've got some really good cards for the match, like Touch the Spirit Realm, to exile their artifacts and relevant creatures, plus Solitude, halting the combo by exiling a Painter's Servant in response to activating Grindstone.

Getting an early Thalia is also a good way to slow down the deck, but it's usually not enough. It is best to focus on creatures with haste, trying to put as much pressure as possible on our opponent.

The deck has a few versions, with Red being the most popular, despite a Monoblue version taking the last Challenge. Generally, the sideboard doesn't change much: Ballistas help to remove some important creatures, such as Goblin Welder and Painter's Servant itself, and Loran and Cathar Commando come in as extra removal, with the former being very important for destroying Urza's Saga. I've seen some players running Leyline to stop cards like Welder and Goblin Engineer, but I don't think that's a very efficient plan.


This match-up isn't ideal. The presence of Snuff Out and Reanimate spells can put us back on our heels if one of our creatures is reanimated, and the likelihood of our opponent getting Griselbrand on the first few turns makes it difficult to keep the Initiative. Nevertheless, it's our best plan for Game 1, so remember to keep removal open to try and steal back the Initiative.

After sideboarding we cut a few Seasoned Dungeoneers to avoid them getting reanimated. We usually try to win with creatures that hinder our opponent's game, such as Thalia and Containment Priest. Elite Spellbinder is also efficient, locking up their key cards. Not to mention the presence of Leyline. Another reason to remove Dungeoneers is because of Leyline. With it in play and no way to remove it, the best plan for the opponent is to reanimate our creatures, and Dungeoneer is one of their favorite targets due to its ability.


Playing against this matchup is usually not ideal, especially when they have the ability to get plenty of creatures on the board early on and back it up with Snuff Out to clear the board of any creature with initiative. Furthermore, they can potentially get an early Natural Order, which usually means massive, and often lethal, damage. Being on the play is extremely important here, allowing you to get the initiative early and protect and control other creatures with our removal. Solitude with Touch is insane here; just be careful of Snuff Out once again.

Ballistas are very important here, as they can take out multiple creatures and further protect ours. Generally speaking, there's not much of a secret: keep hands that can get the Initiative early and have the capacity to protect it for at least one turn, and then let it do the rest of the work.


This deck has the ability to win on turn 0 without you even having to cast any spells, but overall the matchup is good because Thalia shuts down the deck's spells and they can't go ahead. She can also accelerate the clock, putting them in the red zone when they try to play Doomsday. Elite Spellbinder increases the amount of mana needed to activate key spells, hindering our opponent from accomplishing the combo in the early game.

After sideboarding, we took out some creature removal and put in more  creatures to increase the pressure. Loran and Cathar have great targets like Lotus Petal and/or Lion's Eye Diamond. This match it's a race, look for aggressive hands and/or ones that can play Thalia on turn one. We must keep some removal spells in the deck, as we can still potentially face Thassa's Oracle.


It's another match-up that's often play/draw, but not always. It doesn't do any good to be on the play without having any creatures with Initiative, but it doesn't help to be on the play with them if your opponent has something to remove them, like Solitude or Swords to Plowshares. What really makes the difference, whether you're on the play or not, is who has more creatures with Initiative, at least in Game 1. Another great move when you're on the play is to cast Elite Spellbinder, locking down an important card and then following up with an Initiative creature, giving you the chance to easily steal it back later, even if your opponent eventually gets another one.

Post-side, Thalia is the worst card, and creatures with protection from white help to keep the board from getting out of control, but practically every list is running 4 Walking Ballistas, so their importance has diminished somewhat, but not by much. Mulligan hard for the most unfair hands you can, resolving multiple creatures with Initiative. Post-side, don't let your opponent get too comfortable in the game by going after Ballistas and Kannushi/Archon to avoid falling too far behind.


It's interesting to note that, overall, the deck doesn't have many favorable matchups, but that just goes to show how resolving creatures with "Initiative" early can turn a bad match into something favorable for us. It's a powerful deck, with elements of taxes, efficient removal, and a truly broken ability. I don't know if it will ever be banned, but it's sure to continue appearing in the tiers and causing a lot of controversy among players of the format.

Until next time!

If you liked this article maybe you will also find interesting on of the following ones Taking the Modern Challenge with Calibrated Blast: primer and sideboard guide, Monored Anax primer & sideboard guide

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Lucas Giggs
MTG Streamer
Hi, my name is Lucas de Almeida Hervás. I'm 31 years old, married, and I live in Indaiatuba/SP, Brazil. I've been playing Magic the Gathering since 2009, but I've been making a living off of it since 2019 through leagues and tournaments on Magic Online. For those who don't know me, I'm 2.17 meters tall, hence the nickname "the tallest Magic player in Brazil."


Published: 2023-02-05 00:00:00

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