I wish he was in the base game.

give cat another gun

passive that gives armor somehow ( •̀ ω •́ )

some cool things i thought of while sleepy:
item in witch you passivly gain gold. entill you are hit in witch it breaks and gives no more gold :(
status effect discription
curses in items once picked
secret unlocks :0 (could be cool, idk lol)
make it so some items can be found and bought multiple times getting rarer and rarer each time
make stop and skip not kill you maybe

a hand that pets the cat once and dissappears

Catnip that makes them slower and deal less damage but make them take less and have armor

i have a suggestion : doing a thing that is popular with other roguelikes : differents starting loadouts
you could unlock them by doing specific conditions
you could choose the one you want using the mod option mod

they could be things like :
- greed build : start with some money at the start, reduce money gain
- curse build : start with 3 positive and negative random curse effect
- lock build : more items available in shop, less money gain
- aerial build : no free cancel, two air options by default
- your only moves build : no moves available in shop, but all upgrades are way cheaper
- monk build : no upgrades available in shops, all moves are way cheaper
- crypto build : a random upgrade/move of your char is removed every x delay, give you a lot of money in exchange
- jjk build : gives you a free unpunishable counter that works on burst, 10 differents teleports, and a insta kill screen wide move
...

please put a list of what all the items do in a bit more detail