I want to summon chickens to peck people to death. In all seriousness, summons should basically be positives. I think they should last as long as you want as long as you don't let the enemy attack it till it goes away(they shouldn't have op health). Would be cool if you could customize the kind of animal you get, like just certain colors and stuff so it seems like more of a partner and not everyone has the generic toad, snake or whatever. Also you should have no real control over your summon and should be careful it doesn't get in the way of your own attacks.