B · Engine & Sequencing · §7
The Legend is an evacuation tool before Empower and a tempo engine after it — but only on your turn.
Akali, Rogue Assassin can Empower for 3 Energy and one Power. Her Action exhausts the Legend to move a friendly unit in a showdown to base, but only on your turn. If the Legend is Empowered, the moved unit is readied.◆src
You can attack, force combat, observe opposing reactions, return the unit to base, and preserve it for a later turn. The unit remains in whatever readiness state results from the sequence, so the retreat does not automatically create another attack.
Move a ready unit to a battlefield, open or enter a showdown, force the opponent to commit, exhaust the Legend, move the unit to base, ready it, and move it to another battlefield later in the turn. The second battlefield does not need to be the original objective — the threat of the first conquest can exist primarily to pull resources away from the second.
The strongest opponent response is often simply to spend the minimum necessary and force you to decide whether preserving the unit is worth abandoning the point.
That threshold can be a premium combat trick, a removal spell, multiple defenders committed to one location, an activated ability that cannot be reused this turn, enough Energy spent that another battlefield becomes vulnerable, or a card whose value depends on combat completing favorably.