when corruption puts a static barrier on a target the target also gets the buff "sustaining darkness" which is supposed to heal n * # of sustaining darkness stacks left of target when static barrier drops. which works the vast majority of the time when static barrier gets broken from damage early. but when the barrier is not broken and expires it does not heal for the sustaining darkness heal. so like if someone is around 95 % and they aren't gonna take damage for a sec its not worth it to throw a dark heal so you just bubble bc it will heal em up..but then it doesn't.