Volrath, the Shapestealer + Psychic Frog + Evolution Witness + Workhorse

Volrath, the Shapestealer

Psychic Frog

Evolution Witness

Workhorse

How it works

1. Activate Volrath by paying 1, causing it to become a copy of Psychic Frog until your next turn.
2. Activate Volrath using Psychic Frog's ability four times by discarding four cards.
3. Holding priority, activate Volrath by paying 1, causing it to become a copy of Evolution Witness until your next turn.
4. Resolve the first Volrath ability from step 2, putting a +1/+1 counter on it.
5. Volrath triggers, returning a permanent card from your graveyard to your hand.
6. Repeat steps 4 and 5 for each remaining ability.
7. Activate Volrath by paying 1, causing it to become a copy of Workhorse until end of turn.
8. Activate Volrath using Workhorse's ability three times by removing three +1/+1 counters from it, adding CCC.
9. Repeat.

This intricate loop turns Volrath, the Shapestealer into a shapeshifting engine of recursive value by cycling through the abilities of your other permanents. You start by using Volrath's copy effect to borrow Psychic Frog's discard ability, pumping it with counters and triggering its synergy. By shifting the copy target to Evolution Witness, each of those placed counters triggers the Witness's passive ability to return a permanent card from your graveyard straight back to your hand. Finally, swapping over to Workhorse lets you cash in those accumulated counters for a tidy sum of colorless mana to keep the entire transformation cycle spinning.