Out of 10 arena matches today the avenger talisman post death buff did not work on 9 of them. The revenge icon shows up on the characters and then disappears. Looks like a bug.
There were defenses with primordial and defenses without primordial so it doesn't look like it's related to all the shit that happens with it. It's really weird and annoying because this feature is the highlight of this talisman set imo.