Underworld Connections

Whenever another creature you control with power 2 or less enters, you may pay 1. If you do, draw a card.

Return all creature cards from your graveyard to the battlefield. Each of them is a 1/1 Spirit with flying in addition to its other types. Exile Storm of Souls.

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and T no matter when it came under your control.) Equip 1 (1: Attach to target creature you control. Equip only as a sorcery.)

Each player reveals the top card of their library. For each creature card revealed this way, create a token that's a copy of that card, except it's 1/1, it's a Spirit in addition to its other types, and it has flying. If no creature cards were revealed this way, return Haunting Imitation to its owner's hand.

T: Add one mana of any color in your commander's color identity.

At the beginning of each player's draw step, that player draws an additional card.

Whenever this creature or another nontoken Vampire you control dies, create a Treasure token. (It's an artifact with "T, Sacrifice this token: Add one mana of any color.") R, Sacrifice two artifacts: Exile the top card of your library. You may play that card this turn.

4BB: Exile target creature and put a +1/+1 counter on this creature. This creature has all activated abilities of all creature cards exiled with it.