I thought about this while I was playing a Call of Duty game the other day, basically we could have a prestige system for credos, for those who don't know, the prestige mode is an option available to players after reaching the highest possible rank in multiplayer in the popular first-person shooter video game franchise published by Activision known as Call of Duty.
Players would have the choice to reset a certain credo after completing it if they wish to increase it's prestige level. The amount of quests needed to complete the credo each prestige level would increase everytime it's been reset.
Just like in the popular fps series Call Of Duty players would get additional rewards for going the extra mile, after increasing their credo prestige level players would unlock either very small boosts to existing buffs or even new buffs or simply just cosmetics/vanity stuff such as like being able to display your prestige 5 fisherman credo through an emote that shows a golden fisherman credo badge for example.
I feel like this would be a fun way to let players further enjoy credos since we're only able to do them once per account every world, they're great content and replayability should be possible without having to make an alt.