Butterfree uses poison powder or toxic on togekiss.
Togekiss is poisoned and then uses its move.
Butterfre uses psychic.
Psychic moves (and ground as well) are super effective against poison. Would a psychic or ground move gain power?
No, status problems do not cause Super Effective hits. The power of the move will remain the same, unless if it's a move like Venoshock that causes double damage opon poisoing of the opponent. This does not count as a super effective hit, though it is still worth the same.
No, the power will remain the same regardless of any status.