Solar Array + Tough Cookie + Pemmin's Aura

Solar Array

Tough Cookie

Pemmin's Aura

How it works

1. Animate Solar Array, if needed.
2. Cast Pemmin's Aura by paying its mana cost, attaching it to Solar Array.
3. Activate Solar Array by tapping it, adding and causing the next artifact spell you cast this turn to have sunburst.
4. Activate Pemmin's Aura by paying , untapping Solar Array.
5. Repeat from step 3 as desired.
6. Cast any artifact spell, triggering its sunburst ability an infinite number of times, either putting infinite +1/+1 counters on charge counters on the artifact.