Kalamax, the Stormsire, and Expansion // Explosion

Prerequisites

• Kalamax, the Stormsire on the battlefield
• Expansion // Explosion in hand
• plus the cost of the additional instant available

Steps

1. Cast any instant by paying its mana cost
2. Holding priority, cast Expansion by paying its mana cost
3. Kalamax's first and second abilities trigger
4. Resolve the first ability, creating a copy of Expansion and choosing to copy the original Expansion
5. Resolve the second ability, putting a +1/+1 counter on Kalamax
6. Resolve the Expansion copy, creating a copy of Expansion
7. Kalamax's second ability triggers, putting a +1/+1 counter on itself
8. Repeat from step 6 any number of times

Results

• Infinite +1/+1 counters on a creature
• Infinite magecraft triggers