Flying, lifelink
If you would gain life, you gain twice that much life instead.
When Selenia dies, create a legendary black Aura Curse enchantment token named Selenia's Curse attached to target opponent. The token has enchant player and "If enchanted player would lose life, they lose twice that much life instead."

+2: Create two 1/1 blue Bird creature tokens with flying.
0: Draw a card. You may put a permanent card with mana value 4 or less from your hand onto the battlefield.
−7: Create a Feroz's Ban token. (It's a artifact with "Creature spells cost more to cast.")
Feroz, Ulgrotha's Warden can be your commander.

When Perforator Crocodile enters, for each creature your opponents control, conjure a card named Stab Wound onto the battlefield attached to that creature.
Cycling

+2: Create a Giant Badger token. (It's a 2/2 Badger creature with "Whenever this token blocks, it gets +2/+2 until end of turn.")
−3: Mill three cards. Put all permanent cards from among them into your hand.
−8: Until end of turn, creatures you control have base power and toughness 8/8 and gain trample.
Greensleeves can be your commander.

Flying
Once during each of your turns, you may pay rather than pay the mana cost for a spell you cast from exile.
Whenever Dragon's Smile deals combat damage to a player, that player exiles that many cards from the top of their library. You may play those cards this turn.
Crew 3

Rulebreaker — A deck with this commander can have any land cards.
Whenever Grizzlegom attacks, create a 1/1 white Soldier creature token for each Plains you control. Draw a card for each Island you control. Each opponent loses 1 life for each Swamp you control. Put a +1/+1 counter on Grizzlegom for each Mountain you control. You gain 1 life for each Forest you control.

Whenever you cast a permanent spell with in its mana cost or activate an ability with in its activation cost that isn't a mana ability, you may have the value of X become 5. Do this only once each turn.

Rulebreaker — A deck with this commander can have creature cards with mana value 7 or greater of any color identity and any basic land cards.
Whenever a creature you control with mana value 7 or greater attacks, double its power and toughness until end of turn.