Can Evolutionary Kaisa choose a spell that was used earlier in the same turn during the chain that led to the conquer, since it would already be in the trash?

Ruling: Yes, Kaisa can target a spell that was played earlier in the chain that led to the conquer, as it will already be in the trash when Kaisa's conquer trigger resolves.

Sequence:

• Spell is played and activated as part of the chain leading to conquest
• Spell resolves and goes to trash
• Kaisa conquers
• Kaisa's conquer trigger allows selection of that spell from trash to play again