Most likely, Jester's Mask's user will choose a new hand of unneeded lands and/or weak spells for the opponent, which can set them very far behind
Because control takes so long to kill even after it takes over the game, just a few uncounterable damage cards (Urza's Rage) can provide a very important contingency plan
This pushes out players who don't enjoy playing that particular kind of deck, and games will quickly become same-y
(At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever you win a coin flip, this creature deals 1 damage to any target
Its the same feeling you get when you open a booster pack, but amplified
Here are the details for each card: If you are on a PC, you can try to Right-Click the Image and choose 'Open Image in New Tab' for the bigger picture