If the resolution of a triggered ability involves casting a spell, that spell can't be cast if a spell with split second is on the stack.
Celestial Crusader
After a spell with split second resolves (or otherwise leaves the stack), players may again cast spells and activate abilities before the next object on the stack resolves.
Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a white creature may become lethal if Celestial Crusader leaves the battlefield during that turn.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Jim Murray
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