Infinite +1/+1 counters on a creatureInfinite +1/+1 counters on a creature token
How it works
Cast Enduring Scalelord by paying 4.
Holding priority, activate Lithoform Engine's third ability by paying 4 and tapping it, copying the Enduring Scalelord spell.
Resolve both Enduring Scalelord spells.
Put a +1/+1 counter on either Enduring Scalelord.
The Enduring Scalelord who didn't have the counter put on it triggers, putting a +1/+1 counter on itself.
Repeat step 5.
This clever loop relies on a pair of Enduring Scalelord cards—one cast normally and its exact copy created by Lithoform Engine—feeding into each other's triggered abilities infinitely. Because each Enduring Scalelord sees a +1/+1 counter being placed on *another* creature you control, placing a counter on one triggers the other, which in turn triggers the first back. This establishes a perpetual, self-sustaining loop that generates arbitrarily large creatures without needing any further mana or outside intervention.