As the title suggests, what do you guys think is the most optimal/broken/minmaxed build for a zealot barbarian

Level 20, feats and multiclassing are allowed, any race from any official source and 1 very rare, one rare and 2 uncommon magic items for equipment.

Stats before any racials: 18, 16, 15, 12, 16, 9

Building a character for a stupidly broken 3-4 session mini campaign where our DM said it'd be super combat heavy without lots of spellcasting/magic but he would be trying to kill us every step of the way 😂😂

I think straight zealot would be most optimal but I want to hear your opinions! Thank you all in advance for your time and suggestions!! Appreciate you!!🙏🏻