Red: Deflecting Swat, Bolt Bend , Wylls Reversal , Wild Ricochet, etc
My favorite card might be Minion Reflector
(Choose any number of permanents and/or players, then give each another counter of each kind already there.) Illustrated by Anthony Palumbo Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Legal Brawl Not Legal Legacy Legal Comp
That's all it does
You can power out cards with low or no costs, and at the end, if you had just three artifacts (say an artifact land, a mana rock, and a Silver Myr) then your four Jars will have dug TWENTY-EIGHT CARDS DEEP that turn, and while it was your main turn, so you cast them all (in theory), your foes could only cast instants and cards with flash
And one final note here: These decks are complex