Does Reckoners arena satisfy the blighted battle axe conquer requirements?

No, Reckoner's Arena does not satisfy Blighted Battleaxe's conquer requirement.

Per FAQ 9662, Blighted Battleaxe checks whether the equipped unit specifically conquered a battlefield that turn. Reckoner's Arena activates the unit's conquer effects during a Hold — but the Rules FAQ Clarification (2026-04-29) is explicit that no actual conquer occurs. The game merely treats it as if a conquer happened for the purpose of triggering those effects. The equipped unit still did not conquer a battlefield.

Since Blighted Battleaxe's condition checks for an actual Conquer (not a simulated one), the equipped unit did not satisfy it. At the end of your turn, Blighted Battleaxe will unattach and deal 4 damage to the unit.