The Takatsuki Hall of Fame also seems to be popular, but in addition to banning the cards excluded from official competitive play (sad bird noises), it has some custom rules
"Google's April Fools' prank puts Pokemon in the real world"
If you're not trying to build a complete set, you could flip these for a few nice trades or even sell them to put toward something higher-end, like illustration rares or sealed product
But if you're willing to commit seven mana during your main phase, you get the addendum effect, giving you a free permanent with converted mana cost 7 or less
Creature - Human Wizard Color tag templates(None) Nils, Discipline Enforcer At the beginning of your end step, for each player, put a +1/+1 counter on up to one target creature that player controls