Not necessarily -- I've completed the Library Stage now a few times!

The first time I completed it with my Cleric character. She had Holy Water, Garlic, a Holy Bible spinning around her, grabbed an AoE augmentation and damage increase, then just picked up whatever random thing was given to me.

Second time was with the Lightning Ring character and I focussed on that ability plus whatever I got given.

Then third time was with some other character that I was just testing out. Looks like a panda bear, haha. His ability was the Cherry Bomb... whichhhh I've decided I don't like. But I maxxed it out since it was his inherent ability and just grabbed whatever else was given to me. Still won.

It's more a game of avoidance, in my opinion. Pretty much every weapon will take you to the end as long as you level them up. 😁