The obvious choice was to make a planeswalker with a lot of loyalty abilities, more than any previous planeswalker card
I dont think anyone expected this product to hit big box stores
Since the cards you have gained control of become 2/2 Cyberman artifact creatures, maybe implement cards with the face-down creatures with the morph mechanic
The target opponent has the option to pay 3 life, although the token can't return to your hand
If some, but not all, of the creatures are illegal targets as the triggered ability tries to resolve, the original distribution of counters still applies and the counters that would have been put on illegal targets are lost
The green color identity adds extra depth, letting you turn that mana into game-ending plays with finishers like Craterhoof Behemoth or tutors such as Green Sun's Zenith