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
In fact, it's a shock to many that such a tycoon game hasn't been attempted prioras the fantasy of running a card shop, though niche, is one that's at least somewhat appealing to those in the hobby
The face Commander, Ulalek, Fused Atrocity has the capacity to be total nightmare fuel owing to the fact that it can copy all your spells and triggered abilities on the stack for a mere two colorless mana, every time you play an Eldrazi spell
Be aggressive with an army of creature tokens with the help of the squad mechanic, which lets you create extra token copies of creatures