A creature with a counter on it is considered modified no matter what kind of counter it is or which player put it on that creature.
2022-02-18
A creature that is equipped is considered modified no matter who controls the Equipment that's attached to it.
Flame Discharge deals X damage to target creature or planeswalker. If you controlled a modified creature as you cast this spell, it deals X plus 2 damage instead. (Equipment, Auras you control, and counters are modifications.)
An Aura controlled by an opponent does not cause a creature you control to be modified.
