Rex, Cyber-Hound + Pili-Pala + Vhal, Candlekeep Researcher

Rex, Cyber-Hound

Pili-Pala

Vhal, Candlekeep Researcher

How it works

1. Activate Rex using Vhal's ability by tapping it, adding at least CC that cannot be spent to cast spells from your hand.
2. Activate Rex using Pili-Pala's ability by paying 2 and untapping it, adding one mana of any color.
3. Repeat.

This clever engine transforms Rex, Cyber-Hound into a one-dog mana-printing machine by scavenging activated abilities from the graveyard. First, you feed Pili-Pala and Vhal, Candlekeep Researcher to Rex's exile ability so the Cyber-Hound inherits their text. With those abilities grafted on, you tap Rex using Vhal's text to generate colorless mana, then spend a portion of it alongside Pili-Pala's untap symbol to untap Rex and produce any color of mana. Repeating this loop yields infinite colored and colorless mana, though Vhal's restriction means the colorless portion cannot be spent on spells from your hand.