Player retention suggestion:
Players want to live the 1-character fantasy, but as a new player I made over 10 alts and leveled them up to 5 or 10 before quitting, deleting, and trying again until I found something I like, which goes against the philosophy of "One character can do it all".
Two suggestions:
1: Primordium cost changes - Dyanmic pricing based on the number of relics you own.
Relic(n) = 15 + (n - 1) × 31.9
First one is 15 primordium, second is 47, third is 79. ... 22nd is 684 primordium.
[[ OR ]]
2: Newbie island - Free relic changes!
Allow relics to be traded in freely for exchange until a specific quest is completed. That quest also acts as a gate, preventing the player from leveling any skill past lvl 10, and prevents them from traveling anywhere except the newbie island, cobalt tower, and the newbie dungeon.
Consider it a trial mode.
Once the player makes a decision, the relic cost locks in and prevents the player from trading in relics to try other classes, but allows them to level past lvl 10, and leave the newbie island/cobalt tower/newbie dungeon.
I think these two ideas could help player retention , especially new players who don't want to have to reroll a dozen times to find a class they like.