If you acquire additional gears, skills, and companions at level 100, you will be rewarded with the next level of equipment, skills, and companions for every 5 you acquire.

You will be rewarded with next-level gear, skills, and companions.

Also, items that have reached level 100 will accumulate summon results until 5 items are accumulated.

Ex) Slimy Press Level 100 > Acquire 5 Slimy Press > Acquire 1 Rage.