Cast Chain of Acid by paying {3}{G}, targeting an indestructible noncreature permanent you control.
Lorehold Pledgemage triggers, giving itself +1/+0 until end of turn.
Resolve Chain of Acid, destroying nothing and causing you to copy Chain of Acid, targeting an indestructible noncreature permanent you control.
Repeat from step 2.

Infinitely powerful Lorehold Pledgemage until end of turn

Infinite magecraft triggers

Chain of Acid

Lorehold Pledgemage

Cast Chain of Smog by paying {1}{B}, targeting yourself.
Lorehold Pledgemage triggers, giving itself +1/+0 until end of turn.
Resolve Chain of Smog, causing you to discard two cards and copy Chain of Smog, targeting yourself.
Repeat from step 2.

Combos with "Lorehold Pledgemage"