If Hidden Blade is used to kill a buffed unit before Blitzcrank can grab it, and Sett's legend effect saves the unit, does the unit still count as a legal target for Blitzcrank?

Question

Accepted Answer

Yes — provided Sett's legend effect prevented the unit from leaving the board (it did not change to a non‑board zone), the unit remains the same game object on the board and is still a legal target for Blitzcrank. If Sett's effect moved the unit to a non‑board zone (hand, banish, etc.) or otherwise caused it to cease being the same object, it would no longer be a legal target.

If Hidden Blade was played (from Hidden or not) targeting the unit at that battlefield and Sett's legend effect prevented the unit from actually leaving the board (so it never became a different object in a non‑board zone), the unit remains the same object and stays a legal target for Blitzcrank [359.3.e.3] [811.1.d.2]. If instead Sett's effect caused the unit to change to a non‑board zone (for example it would have gone to hand or been banished) and then returned, it would be a different object and would no longer be a legal target for Blitzcrank [359.3.e.4] [359.3.e.5].

You play Hidden Blade targeting the buffed unit at that battlefield; because the spell targets "a unit at a battlefield," that target must be chosen from that battlefield when the spell is finalized [811.1.d.2] [355.9.a] [355.10.b]. Sett's legend effect intervenes and "saves" the unit. If that effect prevents the unit from dying without moving it to a non‑board zone (i.e., the unit remains on the board the whole time), then the unit remains the same game object and any targeting relationships to it remain intact [359.3.e.3]. Because the unit stayed on the board, it remains a legal target for Blitzcrank (either because it was already chosen by a prior effect or because it still meets the targeting requirements when Blitzcrank looks for targets) per the rule that targets that later meet requirements again are legal [359.3.e.3]. If instead Sett's effect caused the unit to change to a non‑board zone (hand, banish, etc.) and then return, it is treated as a different object and is no longer a legal target for the original spells or abilities that had targeted the original object [359.3.e.4]. In that case, Blitzcrank could not rely on the earlier targeting relationship.

If Sett's effect moves the unit from the battlefield to the controller's Base (a board zone) and back, the unit is still the same object on the board and targeting relationships persist — moving between board zones does not sever the relationship per the guidance in the rules and examples (see [359.3.e.3]). If Hidden Blade was played from Hidden, its initial target choice must be from the battlefield where it was hidden; if the unit left that battlefield (but stayed on the board), it could still be the originally chosen target and become legal again when it returns or meets restrictions again [811.1.d.2] [359.3.e.3]. If Sett's effect changes the unit's characteristics so it no longer meets some specific targeting restriction (for example, a spell targets only "units with a buff" and the save removed the buff), then whether it is a legal target will depend on whether the unit again satisfies that restriction by resolution — targets that cease to meet and then meet requirements again are legal [359.3.e.3]. If the unit is no longer on the board at resolution time (moved to a non‑board zone), the instruction that would affect it is simply ignored for that target and other parts of the spell still happen as applicable (see [359.3.e.5]).

When you play Hidden Blade it targets "a unit at a battlefield," so that specific unit must be chosen from that battlefield as the spell is finalized [811.1.d.2] [355.9.a] [355.10.b]. A targeting relationship is created between the spell and that chosen unit. The Core Rules and official clarifications explain that if a target temporarily ceases to meet the targeting requirements while a spell is on the chain but remains on the board, the spell still "remembers" that it was targeting that object, and if the object again meets the requirements it is a legal target [359.3.e.3] [FAQ:unleashed#22]. The lone exception is when the object changes to or from a non‑board zone (hand, banish, etc.); such a change makes it a different object and severs the targeting relationship, so it would no longer be a legal target [359.3.e.4]. Therefore, if Sett's legend effect simply prevents the unit from dying or otherwise keeps it on the board, the unit remains the same object and remains a legal target for Blitzcrank. If Sett's effect instead causes the unit to move to a non‑board zone (or it was killed and later returned as a new object), it would not be the same object and would not be a legal target for the original targeting attempt [359.3.e.4] [359.3.e.5].