Instant and sorcery spells you control have split second. (As long as a spell with split second is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
"I have slowed the suns themselves. Do you truly think your pulse will fare any better?"
(21/08/2026)
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.
(21/08/2026)
Casting a spell with split second won't affect spells and abilities that are already on the stack.
(21/08/2026)
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.
(21/08/2026)
Split second doesn't stop triggered abilities from triggering. If one does, its controller puts it on the stack and chooses targets for it, if any. Those abilities will resolve as normal.
(21/08/2026)
Players still get priority while a card with split second is on the stack; their options are just limited to mana abilities and certain special actions.