Dockside Extortionist commonly comes down and just takes over the game
If a player just ramped two lands into play, you can end step flicker your Knight of the White Orchid with Ephemerate, and then enjoy getting a second land on your upkeep
#7 Both terrible and great
It's interesting to note that Lightning Rift (more on this card below) came from design without any mana cost when it triggered and development added one
Liliana, Heretical Healer [Best Token Multiplication for Explosive Board Expansion] Liliana, Heretical Healer blends recursion, discard, and planeswalker value into a compact engine that supports Zombie-centric attrition
She attacked you!" It's a typical Hydra otherwise, it enters with Power and Toughness equal to the amount of mana you put into it, but that funky activated ability can make for some fun, and contentious, table moments