Nov 5, 2017
So let’s say I have kataki’s war wage out against affinity. On their upkeep I try to remind them of it, but they’ve drawn a card before I can get the words out. Let’s say this is at like a GP or a SCG Regional or something- what happens?
Kataki grants the triggered ability to each artifact in play, so it’s the controller of those artifacts who is responsible for remembering the triggers and resolving them properly. If your opponent misses these triggers, then it’s too late for them to be able to pay any of them and you, as that player’s opponent, will have the option to have the default action of sacrifice carried out for each trigger missed this way. Your opponent will also receive a warning for the missed triggers.