Ambessa's Legend becomes empowered whenever you empower something else, then spends that charge and one Power to ready a unit. This list charges it cheaply with Legion Marauder, readies large units like Vi, Peacekeeper the turn they arrive, and uses its Might spells to win both combats and Rampage or Challenge exchanges.
Key Cards
Matriarch of War only does something after you empower another card, so Legion Marauder matters more than its size suggests: its Empower costs one Energy or one Body Power and charges the Legend for a ready. Vi, Peacekeeper is the unit I would most want to ready, since her attack trigger stuns an enemy unit at that battlefield. Ambessa, The Wolf is the chosen Champion, and once empowered she has 7 Might and can't be dealt damage outside combat, which makes Rampage and Challenge one-sided while she waits at base.
Ambessa rewards you for planning the turn before the fight starts. Whenever you empower something else, Matriarch of War becomes empowered too. You can then disempower and exhaust the Legend, paying 1 Power, to ready a unit. That lets a newly played unit at base make its first move this turn, or lets a surviving attacker act again. The ability has neither Action nor Reaction. Use it during the open part of your own Main Phase, not during a Showdown or in response to a removal spell. Decide what you will ready, what it can legally reach, and how you will protect it before committing to combat.
How Ambessa wins
Build a unit the opponent cannot trade with cheaply, clear the defender in its way, then use the Legend's ready to make the turn harder to contain. A large unit also improves Public Execution and the damage from Challenge or Rampage, so growing your board can remove theirs at the same time. You do not need to spend the ready on the unit you empowered. Sometimes the better attack comes from a second unit that just entered at base. If your first attacker is already at a battlefield, check its movement: readying it does not give it Ganking or a direct route to the other battlefield.
Key interactions
Let The Wolf clear the fight before entering it
Ambessa, The Wolf · Rampage · Challenge
An empowered Wolf is 7 Might and cannot be dealt damage while she is outside combat. Use Rampage or Challenge while she is at base and she deals her Might to the enemy without taking the return damage. These spells do not start combat by themselves. Paying Rampage's extra Body Power also gives her +2 Might first, so an otherwise unmodified empowered Wolf deals 9. The protection stops as soon as she is in combat; a damage spell can hurt her there just like combat damage can. Challenge has Action and can be played in an open Showdown, but Rampage cannot. Neither is a Reaction to a spell already on the chain.
Use the Might boost before Public Execution
Guttural Roar · Punch First · Public Execution
Public Execution kills an enemy with strictly less Might than the friendly unit you choose. An empowered Wolf at 7 Might can kill a 6-Might enemy; an equal 7-Might enemy is out of range. Guttural Roar gives an empowered unit +4 for the turn, putting that Wolf at 11 and bringing a 10-Might enemy into range. Let the boost resolve, then play Execution. Punch First gives +5 whether the unit is empowered or not, but costs 2 Body Power as well as its 1 Energy. Use the cheaper boost that actually reaches the target. Roar and Punch First have Action, not Reaction, and Execution has neither, so make this removal sequence during your own open Main Phase.
Grow Kayle without counting extra Legend readies
Kayle, Justified · Matriarch of War
Kayle gains +2 Might for each Empower, reaching 5, 7 and then 9 Might. At three she also gets Deflect 3 and Ganking, which gives her the direct battlefield-to-battlefield move an ordinary readied unit lacks. Each of those Empowers charges Matriarch, but charging a Legend that is already empowered does nothing extra, and it never readies the Legend. If you already exhausted it to ready a unit this turn, growing Kayle again does not buy another activation. Plan around one useful Legend ready, and remember that Deflect makes enemy targeting cost more rather than preventing it.
Strengths
The Legend can ready a newly played threat at base, so the opponent has to consider an attack from a unit that was not on the board when your turn began.
Might does two jobs: it wins combat and sets the reach of Public Execution, Challenge and Rampage. An empowered Wolf can use the damage exchanges safely while she stays outside combat.
Empower upgrades can carry into later turns. You do not have to keep spending a new pump spell just to make the same unit a credible threat.
Weaknesses
Empowering a unit, paying for the Legend and protecting the attack all compete for resources. A large unit with no Power left for the next play can leave you with fewer options than two smaller units.
Readying does not heal a unit or give it Ganking, and the Legend cannot be activated during a Showdown. Check the unit's damage and its next legal move before spending the ready.
This is my Ambessa pick because it has cheap ways to charge the Legend and expensive units worth readying. Legion Marauder can empower for one Energy or one Body Power, and every time you empower something else, Matriarch of War becomes empowered too. That charge turns into a ready for one Power of any domain, which lets Vi, Peacekeeper or Rengar, Trophy Hunter move out of base on the turn you play them. Vi is the attacker I would most want to ready, because her attack trigger stuns an enemy unit at that battlefield and a stunned unit deals no combat damage that turn. Kennen, Keeper of Balance gives you the same effect on defense: hide him at a battlefield you control, then play him there when the opponent attacks and pay two Energy to stun an attacker. The other half of the deck is raw Might. Punch First, Onslaught, Primal Strength and Guttural Roar win combats, but they also raise the damage from Rampage and Challenge and the reach of Public Execution. An empowered Ambessa, The Wolf can't be dealt damage outside combat, so a Rampage with her at base can remove an enemy unit without taking any return damage. Just remember that each Marauder can only empower once. After those cheap charges are gone, Kayle's three-Energy Empower, which she can take up to three times, is what keeps the Legend working.
The Game Plan
Early gameKeep a two-Energy unit you are happy to empower. Legion Marauder becomes three Might for one Energy or one Body Power, and Noxian Emissary's Empower costs one Energy and one Order Power, after which it leaves two 1-Might Recruit tokens at your base if it dies. Either empower also charges the Legend. Irresistible Faefolk can pull an enemy unit into the battlefield it moves to, and Pit Rookie puts a lasting +1 buff on another friendly unit. Kennen costs three Energy from hand, but hiding him at a battlefield you control for one Power of any domain can be the better early use.
MidgameThe Legend's ready has neither Action nor Reaction, so use it during your own Main Phase, usually on a unit you just played at base so it can move this turn. Vi, Peacekeeper costs five Energy and one Order Power, and Rengar costs five Energy and one Body Power and can be played straight to a battlefield where the opponent has units. Both can also Ambush into a battlefield where you already have units, and a unit that joins your attack that way still becomes an attacker, so Vi's stun triggers. First Mate is your second ready when the Legend is already exhausted. Lucian's Weaponmaster has nothing to equip in this list, so his value here is that he readies the first time he conquers each turn.
Late gameCount the Might you need before choosing a spell. Punch First gives +5 for one Energy and two Body Power, Primal Strength gives +7 for four Energy and one Body Power, and Guttural Roar gives +2, or +4 to an empowered unit, for two Energy. Those three are Actions you can use in a showdown. Onslaught gives +6 for four Energy but only during your own Main Phase, and its Flow lets you play it again from the trash for four Energy before it is banished. Public Execution kills an enemy unit with strictly less Might than the friendly unit you choose, so let the boost resolve first. Tactical Retreat is a two-Energy Reaction that turns your unit's next death that turn into a heal, exhaust and recall, so the unit survives even though it leaves the battlefield.
Battlefields
Blind
Risen Altar · Kayle, Justified · Ambessa, The Wolf
Altar makes the Empower costs of your units here one Energy or one Power cheaper. Kayle empowers for two Energy here, the Wolf's payment drops as well, and every one of those empowers also charges the Legend. The reduction only applies to units at Altar, and it doesn't pay the Legend's own ready cost.
When the Might spells decide the fights
Sandswept Tomb · Punch First · Public Execution
Each spell that chooses one or more units here that are friendly to it costs one Power less. Punch First on your unit here costs one Energy and one Body Power, while Challenge and Public Execution choosing your unit here only need their Energy. The discount depends on where the friendly unit is standing, and the opponent's spells get the same discount on their own units here.
The Wolf's protection does not stop an outright kill, recall or banish, and it does not stop damage while she is in combat. Spreading your threats matters when the opponent can remove the unit you spent the turn upgrading.
When you need a second attack
Star Spring · Vi, Peacekeeper · First Mate
The first time you play a non-token unit here each turn, you may move another unit you control here back to its base. Playing Vi or First Mate here can send an exhausted attacker home, and First Mate's own trigger or the Legend can ready it to move out again. Moving a unit here doesn't activate Spring, and it doesn't return the unit to hand. Check that Spring still has a defender afterward if its point matters.
Sideboard
Answer Gear without losing a card
Salvage
Bring the two Salvages when an opposing Gear is driving the game. Salvage is an Action that can kill a Gear and draws a card even if you decline the kill. Replace interaction that has poor targets rather than the small units that charge the Legend.
Protect the committed threat
Repulse · Decree of Strength · Sabotage
Repulse protects a friendly unit at a battlefield from an enemy spell or ability that chooses it and no other friendly unit, and at Sandswept Tomb it only costs one Energy. Decree of Strength takes a Mind card from the opposing hand, including a unit, while the second Sabotage takes a non-unit card. None of them covers every answer, so choose based on what is breaking your important turn and trim a pump spell you don't need.
Win the large-unit exchange
Public Execution · Ambessa, Respected and Feared · Kayle, Justified
The second Public Execution is for boards full of units your boosted attacker can outsize. Ambessa, Respected and Feared costs five Energy, and her Empower costs one Energy and two Order Power; while empowered she has Assault 2 and kills an enemy unit at her battlefield with less Might than her when she attacks. Empowering her also charges the Legend, but with four Order runes that payment is the limit to plan around. The third Kayle adds another unit that can take all three Empowers. Bring them in for a Faefolk or a combat trick when the opponent's units are large rather than numerous.
