2R: Target creature attacks this turn if able.
It's a 2/2 for three mana, so it's already on the edge of playable/non-playable line. I supposed the Heckling Fiends might be good in limited. I think it's a higher pick than something like the vanilla Riot Devils, for example. But I think it really only works for specific archetypes.
The black/red and green/red archetypes like to be aggressive. Heckling Fiends would be less good in that deck, for example. Blue/red on the other hand likes to be more controlly and I think the fiends would be a better fit in that type of deck.