What team can beat KRU relic 4?

Killing KRU always requires a bit more thinking than other toons. A couple toons like scav Rey that hit really hard, a dazer, and a taunter go a long way against a KRU team. If your damage dealers don't kill faster than his regen you are likely in trouble, but that is where that daze can come in.

He's actually similar to kill like Nest.
In which case an easy answer is always:
Nihilus.