Nobody Saves the World

This achievement requires you to reach level 30 overall. Once you do, you'll unlock the ability to equip four passive abilities on all of your Forms. You'll need at least four Forms unlocked so you have a passive available from each one to combine on one Form, but you'll need to unlock enough Forms and level them up for you to rank up to level 30 anyway.

Leveling up happens only from completing challenges and quests, not from killing enemies, so don't bother farming enemies unless you're purposely working on a challenge. Either way, by the time you're done with all of the necessary dungeons in the game and by the time you reach max rank in all three Guilds, and level up all Forms to S rank, you'll likely be around level 50 by the end of your first playthrough, possibly higher. So this achievement will become available along the way to obtaining Super Wiz (100G).