Hm. This has taken an interesting turn as we have people favoring beneficial abilities over new possible status effects.
We didn't have many suggestions for abilities to so we're open to suggestions right now.
Current abilities already suggested:
Mitosis or a similar duplicating ability.
Sorry if I missed something, but
granting creatures mitosis or a similiar duplication effect, wouldn't work much differently than the mitosis spell, except you could give mitosis to one creature each turn and the swift-creature itself would be another source of attack power. Aside from these additional benefits, this concept seems pretty redundant to me...