mtg 12 card booster Dominaria United Set Pack (12 Cards) 20 Basic Lands) Pack 9/12 of an MTG:

Balmor, Battlemage Captain For an uncommon legend, Balmor, Battlemage Captain is packing heat in its archetype

Ratchet Bomb is a universal, albeit slow, way to deal with stuff

This does still require a lot of setups, which is why it doesnt rank higher than this, but I can see a lot of decks wanting this card and also finding it very rewarding to build around it as the commander

In Pauper Commander you can have any uncommon rarity creature be your commander, and then the rest of the cards have to be commons

Saruli Caretaker There are just a handful of defender creatures that handle mana fixing

However, that Commander's Sphere has use once you no longer need the mana it provides