Red spells (like Fireball) are known for dealing the most damage to opponents overall, so the Mox Ruby card can be invaluable for red spell users
I initially added a lot of colorless lands: Strip Mine and Wasteland to control nasty lands on the other side of the table, Winding Canyons for flash purposes, and more
(The copy becomes a token.) Legendary Creature Artifact - Robot Pinnacle Emissary Whenever you cast an artifact spell, create a 1/1 colorless Drone artifact creature token with flying and "This token can block only creatures with flying." Warp (You may cast this card from your hand for its warp cost
You can put both triggers on the stack, then resolve Displacer Kitten's first, have it blink The Fourth Doctor, then trigger The Fourth Doctor and generate a Food Token
If an effect like Hardened Scales is an auto-include in these decks, a full-on counter-doubling effect is going to be a rather exciting prospect