If I were to deal combat damage with Hapatra, Vizier of Poisons and Ammit Eternal at the same time, could I have Ammit's effect resolve last and Hapatra's resolve first, targeting him to place a -1/-1 counter on and then removing all of them due to his effect?
Yes. Since you control both triggers, you can put them on the stack in whatever order you want. So, you put Ammit Eternal's on first and then Hapatra's. Hapatra's resolves to give it a counter and then Ammit Eternal's resolves to take it away.
Assuming both Ammit Eternal and Hapatra deal combat damage to a player, the former's second ability and the latter's first ability will trigger at the same time (C.R. 603.2), so will go on the stack at the same time (C.R. 510.3, 116.5, 603.3). Since you control both abilities (C.R. 112.8), you can put them on the stack in either order, including in the order you state (C.R. 603.3b).
On this exact interaction with these two cards, who puts the Counter on Ammit Eternal? Hapatra, Vizier of Poisons say whenever YOU put a -1/-1/ counter, and Ammit says "Whenever Opponent cast a spell, PUT a -1/-1 Counter on it"...
The controller of the trigger, so the controller of its source, so the controller of the Ammit. The opponent casting a spell is just the trigger condition, that player has nothing else to do with the trigger.
If I were to deal combat damage with Hapatra, Vizier of Poisons and Ammit Eternal at the same time, could I have Ammit's effect resolve last and Hapatra's resolve first, targeting him to place a -1/-1 counter on and then removing all of them due to his effect?
Thanks.
Former Rules Advisor
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