Need a strategy to take down Killer Prime in Purgatory? Doesn't matter the mode normal kills me as easily as hard. Haven't even made it to madness.

I just can't do enough damage to take him down (having that problem all the time these days)

I've only been able to beat him with my trooper's Daedalus.

I don't have prisoner which has made all of the newest levels a pain.
I don't have many relics.

I can survive particularly if I use Magus Lillith but I'll never do enough damage before he heals. Heal block and disable passive almost never work on him.

Lately I've been trying

Beast Eddie (Nightmare/Future) & DDE (Immortal/Flash)
Madam (Destiny/Advantage)
Horus (Energy/Future)