There already is an “easy mode”. It’s an RPG, you can just over-level yourself and max out your weapon upgrades if it’s too hard. If that’s not enough you can summon two whole players to do the fighting for you.
To prep for the DLC I made a new character, beelined it to my favorite spot to grind runes, and with my character at level 100 I just went through the world 1/2-shotting all the mobs. Then for all the bosses I couldn’t kill in a handful of shots I just summoned two people to help. It does take patience but you can make the base game an absolute cakewalk.