Kael, Hollow Failure

Whenever a creature would get +X/+Y until end of turn, it gets -X/-Y instead. (For example, if a creature would get +2/+1 until end of turn, it gets
-2/-1 instead.)
Whenever any number of +1/+1 counters would
be put on a creature, that many -1/-1 counters are put on that creature instead.
His spark left him empty and fragile, a feeling that all who see him would know well.