Massive Duck. C.M.
Banned
I have. I've done it with Attikus, actually. It's easy to do with him. A few tips:
Invest in talents that either cause lifesteal or health regeneration. At level 3, he gets the "Brawler's Boon" talent which grants lifesteal on his basic attacks, though "Tenacity" is also good if you want to melt targets quickly. At level 5, always take "Hedronic Regeneration", as this gives you insane sustain; just build up to full charges, and let the health flow. Always take the "swift strikes" talent at level 7, too. Attikus benefits way more from attack speed than more health.
If you need to get the hell out of dodge, just pounce out. Save pounce for escapes. Also get the talent which makes Attikus' shields recharge during your pounce, it'll save your ass sometimes.
For gear, I'd get attack speed, attack damage and health regen. I've got a green attack damage item that grants +attack speed on a melee hit, I've got just a gray attack speed item, and I've got a purple health regen item that also grants +attack damage passively. This combination of gear is great for Attikus, in general.
When you get to Rendain, never fight him or the boss rush on the middle platform. Go to one of the other platforms, and put your back to a wall. Also regarding the challenge itself, the sweet spot for crits on Rendain is his head, but hitting with charged hook is rather difficult. Try to aim a little above his head, and don't charge it; you want as many attempts as you can. You can only crit him during the stage where he has no shield. I won't lie, you'll probably have to play "The Heliophage" multiple times with Attikus to get that lore challenge done; landing crits on him is that difficult.
Thanks man, I'll give this a try soon!