Can I play Voidmage Husher to counter abilities like Door of Destinies or Edgar Markov, and if it does, do they/all creatures they control lose +1/+1 counters they gained from it?
Also, is the countered ability permanently countered/seize to exist?
There is a rules forum where these types of questions are usually answered. This forum is for unconfirmed cards, not cards that have already been released.
The voidmage can not be used to counter Door or Edgar. Voidmage only counters Activated Abilities, you can always tell an activated ability because they are written {cos}:{effect}.
To answer the rest of your question lets use Voidslime, it can counter triggered abilities. A triggered ability can be identified by the words "when," "whenever," or "at", which will usually be found at the start of the ability.
You can counter the Charge counter adding on Door and both the Eminence and the attack ability on Edgar.
If you counter either ability that adds counters it will not remove existing counters from the permanent.
Even if you counter one of these abilities they aren't removed, so the next time their trigger condition is met, even in the same turn, it will trigger again.
Countering one ability will have no effect on any other abilities from the same card, even if multiples of the same ability are all on the stack at the same time.
Also, is the countered ability permanently countered/seize to exist?
and lastly, does Voidmage Husher counter each ability of a card. For example would Voidmage Husher counter Edgar Markov
"First strike , haste"
and
"Whenever Edgar Markov attacks, put a +1/+1 counter on each Vampire you control.
The voidmage can not be used to counter Door or Edgar. Voidmage only counters Activated Abilities, you can always tell an activated ability because they are written {cos}:{effect}.
To answer the rest of your question lets use Voidslime, it can counter triggered abilities. A triggered ability can be identified by the words "when," "whenever," or "at", which will usually be found at the start of the ability.
You can counter the Charge counter adding on Door and both the Eminence and the attack ability on Edgar.
If you counter either ability that adds counters it will not remove existing counters from the permanent.
Even if you counter one of these abilities they aren't removed, so the next time their trigger condition is met, even in the same turn, it will trigger again.
Countering one ability will have no effect on any other abilities from the same card, even if multiples of the same ability are all on the stack at the same time.
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