The Snapstone Wielder

Legendary creatures you control get +X/+X, where X is the number of legendary creatures you control.

Whenever you cast a legendary spell from your hand, exile cards from the top of your library until you exile a legendary nonland card with lesser mana value. You may cast that card without paying its mana cost. Put the rest on the bottom of your library in a random order.

The Beleaguered Boxer can't be your Commander unless your deck is 100 cards and originally built out of no more than 36 booster packs, plus basic lands.

When The Beleaguered Boxer enters the battlefield, open a Magic booster pack. Remove up to three cards in your hand or graveyard from your deck permanently. For each card removed this way, add a card from that pack to your hand. Those cards are now permanently part of your deck.

As long as this creature is your commander, you may play cards from any game in your deck as long as they can be reasonably translated into Magic. They all fit within this Commander's color identity.

: Create one resource of any type. (Mana or otherwise.)

Whenever you cast a signed spell or play a signed land, copy it. (A signed card is a card signed by its artist, designer, or someone else it's strongly associated with.)

Discard a signed card: Destroy target creature with a name that has a five or fewer letter length difference from the person who signed the discarded card.

+1: Create a 1/1 Human Wizard creature token that's all colors.

−3: Choose a card name from among Enlightened Tutor, Mystical Tutor, Booster Tutor, Imperial Recruiter, and Worldly Tutor. Create a copy of the card with the chosen name. You may cast the copy without paying its mana cost.

−8: You get an emblem with "At the beginning of your upkeep, if you control twenty or more Wizards, you win the game."

Ersta, Friend to All can be your commander.

When Marina Vendrell enters, reveal the top seven cards of your library. Put all enchantment cards from among them into your hand and the rest on the bottom of your library in a random order.

: Lock or unlock a door of target Room you control. Activate only as a sorcery.