You can't cast permanent spells. {4}, {T}: Add {W}{U}{B}{R}{G}. When you cast your next spell this turn, exile cards from the top of your library until you exile an instant or sorcery card with lesser mana value. Until end of turn, you may cast that card without paying its mana cost. Put each other card exiled this way on the bottom of your library in a random order.

Flying, vigilance, haste Whenever Velomachus Lorehold attacks, look at the top seven cards of your library. You may cast an instant or sorcery spell with mana value less than or equal to Velomachus Lorehold's power from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

When Search the City enters the battlefield, exile the top five cards of your library. Whenever you play a card with the same name as one of the exiled cards, you may put one of those cards with that name into its owner's hand. Then if there are no cards exiled with Search the City, sacrifice it. If you do, take an extra turn after this one.

Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies. Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

({T}: Add {R}.)

Create a 0/0 green Ooze creature token with trample. Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity. A deck can have any number of cards named Slime Against Humanity.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats. A deck can have any number of cards named Relentless Rats.