Strict Proctor

Creature — Spirit Cleric

Flying
Whenever a permanent entering the battlefield causes a triggered ability to trigger, counter that ability unless its controller pays .

1/3

2021-04-16:
Triggered abilities use the word “when,” “whenever,” or “at.” They’re often written as “[Trigger condition], [effect].”
2021-04-16:
Effects that modify how a creature enters the battlefield are not triggered abilities and are not affected by Strict Proctor’s ability. These include (but aren’t limited to) effects that have a permanent enter the battlefield as a copy of another permanent, effects that have a permanent enter with counters, and effects that have a permanent enter tapped.
2021-04-16:
Abilities that trigger when something else causes an ability to trigger will always go on the stack after the ability that caused them to trigger. For example, Strict Proctor’s ability will always resolve before the triggered ability that caused it to trigger does. This is a change from previous rules.