Here are a few more!
LEVEL 0 - THE FOOL
(JOIN THE PARTY): For the purposes of sacrifice, this card is considered Level 1.
JUGGLE ACT: Choose a player. They must shuffle their hand back into their deck, then draw a number of cards equal to the number of cards they had.
A bit of Tarot Major Arcana is always fun, and I don't think I saw many hand shufflers? Though I probably missed them. Sorry!
LEVEL 3 - RED FUNGUS
(HOMEGROWN): This card gains all Actions of a single card that was sacrificed to play this one.
(EATUS DETRITUS): When a card is discarded, this card gains 1 Level.
Basically a level regen buff for any one card, but Fun because its Fun-gi. Also doesn't have much innate synergy with Red Paint but potentially could!
LEVEL 2 - WAND OF SWAPS
STRANGE S'TURDAY: Swap the Levels of two cards of your choice. You can't choose this card.
(MAGIC WOBBLE): If this card takes lethal damage, the source takes equal damage.
Simple, fragile and probably pretty powerful. Don't really know!
LEVEL 2 - WAND OF BARRIERS
(LIGHT SCREEN): When played, attach to another card. Damage dealt to that card is transferred to this card.
(SOLAR-POWERED): This card gains 1 Level every turn, up to Level 6, as long as it isn't explicitly nighttime.
The second wand, with quirky recharge. Does real-life nighttime count as "explicitly nighttime"? Hmm...
LEVEL 0 - THE MAW
(SUMMONING FEAST): When played, you may sacrifice any number of your cards. The Maw's level is equal to the combined total of your sacrificed cards' Levels. Additionally, once per turn you may sacrifice one card and add its Level to The Maw's.
DEVOUR: Deals damage equal to its Level, then loses 1 Level.
Build-a-Sweeper kind of card. Don't forget to feed it a steady diet.