I beat the Champion at level 49 after 4 attemps, having no Fabled gear and only 1 piece of ebon.
I tried varios combos of weapn styles, 1h+sheild , 2hander , Dual Weilding (this 1 used 1st and had closes chance, then had success after constant stuns)
I used everybuff I have, potions, and the buffs from rings (and effects will stack if you have more than ring and they dont need to be equiped for the effect to remain)
The weapon combo is used was Pristine Imbuned Cedar Crudgel and the PGT (yes I know its grey but you cant pass up the proc it gives). I know all the post of the forums says that 2 hander is the way to go for a zerker but i honestly cant see why, but then again the only decent 2 hander is the heirophant crook which is my weapon of choice for trails of harclave. For the Champion my success was deal as much damage to him as quickly as i can and to use every stun you have as often as you can. I start with raging blows (which stuns) followed by vanquish (does high damage and stuns) and then frenzy then stunning roar then used no quarter (to get a beserk once it wears off) followed by both rage and infurate (which will give 3 zerk effects). then continued the cycle adding a mutilate, bully (which interupts casting) while waiting for the skills to reset.
thats what worked for me. goodluck
Burlap
Barbarian level 50 Beserker
Permafrost server