Omega Red at 5 covers deals roughly 5% a turn a turn with his passive. But at least you can match away the CD. Here you can not. Plus there is another 5% on top of that to the character in front so that means they are dead in 10 turns (10% a turn) just from the support (more likely in 5 turns when including match damage.
I think all those damage numbers are downsides, hitting the character carrying this support/their team.
It’s an interesting idea (and given this poster, I imagine it’s quite thematic), but I don’t think players would use something that generates so much self damage, even if the effect is very powerful.
The Nullifier is supposed to destroy it’s target so it would be far more thematic if it did something like down a single opponent or destroy the entire board.