Punch does UVs right now, but he could offer a different service as well: gear tweaks.

Looking at weapons, every weapon gets a point of CTR at level 5, and a second point of CTR at level 10. What if, instead of CTR, you could choose what you got?

So, for a small crown fee at Punch (10k perhaps), players could switch their weapon's natural level ability from CTR to either ASI or Damage.

To make this a proper crown sink and prevent confusion involving trade, I think it should only apply to bound weapons, with weapons resetting their ability to CTR when unbound.

Another idea here is to allow special ability upgrades, strengthening the status effects caused by status weapons in exchange for their natural CTR. Might be a little much, but could be cool, and would also make this useful for bombers with status bombs.

Weapons are the main idea here, but it could also apply to armor, trading the 1 or 2 points of HP for a little defense boost or status resist. Yes, this would actually reduce your HP in lower tiers, which could get a little confusing when you're wearing your buffed-out 5* armor in Tier 1 and you have 5 bars of HP. So that's a negative.

Pros: More customization, crown sink, fun with abilities, not luck-based and a use for Punch that isn't "you lost your money on Slime low lol," entirely optional so that it doesn't confuse people too much
Cons: Basically a straight buff to non-charging weapons (esp. Polaris which doesn't need a buff), complexity that might confuse people anyway, is probably best suited for weapons only with armor and shields getting a little weird, you have to pay a little more for your 5* gear that you don't want CTR on