If you just want to stomp the game I think things are easiest with Squirtle and friends by far, since you can build it into a Rain Dance deck later and have something that's out of any of the CPU trainers' league, whereas Charizard and Venusaur aren't as competitively powerful(though Pokemon Center cheese with Venusaur is pretty entertaining...), but you can really get away with doing a decent version of whatever you feel like running so I'd just go with whatever you think sounds fun
Much like Sun Ce earlier, how is there just one of this guy registered on EDHREC.com
Baby Charizard Shows Off His Dance Moves What could be cuter than seeing a dancing baby Charizard
You can exile a card in your hand using suspend any time you could cast that card
In 2015, Wizards of the Coast did just thatthey introduced the Zendikar Expeditions , these special-framed super duper rares were even more difficult to pull from a booster pack
But ol' Niv is a great team player and will happily hop out of the command zone and join your 99, where it's often found in cEDH brews