I am trying to come up with cards that say put a -1/-1 counter on target creature each turn. I already know about
fevered convulsions (which is too much mana to use its ability) and
glistening oil (I don't like the idea of giving opponents' creatures infect). Also be aware that I am looking for continuous effects that work every turn preferably enchantments and that do not only target opponent's creatures (I want mine to be potential targets).