There are plenty of ways to make great use out of a card like Jumbo Cactuar, so long as an opponent doesn't immediately take it out of the game, and even then, it's a great way to reduce the amount of counterpla y at their disposal
If either permanent becomes an illegal target, no counter is removed or put
Youd need to play then banish three Pawpsicles on turns 1 and 2 (youre allowed to target any character and it doesnt need to be damaged) and have Belle Inventive Engineer played on turn 3
Alongside granting this ultra-valuable extra phase, Grim Reapers Sprint even comes with a decent buff too
Its disgusting, but really, you gotta play it when it can cost as little as two mana
Each one gives your commander a bonus that will help them (and therefore help you) in the game