This little icon is to "Ascend" a character.

Pressing this will Reset that Character but in return will gain a permanent boost to their XP gain by 50% and an additional 10% to Pose stat gain.

There is a outdated info on the info box stating that is is 25% increase but it is in fact a 50% due to Release 41 DEVLOG

SPOILERS?

More info,

Characters can "Ascend" more than once.

They keep ascent status after NG+

Requirements are:

• 15 Poses Mastered
• Min LVL. 50
• Max Love?

Hey DEV, mind double checking my info?

This puts a wrench onto my whole plan to just ascend them once then NG+(++++++?)

Rest assured, this is the 6th time Ive ascended a character, and Ive become exceedingly efficient.

This game NEEDS a Wiki.