Kalamax, the Stormsire, and Fork

Prerequisites

• Kalamax, the Stormsire on the battlefield
• Fork in hand
• plus the cost of the additional instant available

Steps

1. Cast any instant by paying its mana cost
2. Holding priority, cast Fork by paying its mana cost
3. Kalamax's first and second abilities trigger
4. Resolve the first ability, creating a copy of Fork and choosing to copy the original Fork
5. Resolve the second ability, putting a +1/+1 counter on Kalamax
6. Resolve the Fork copy, creating a copy of Fork
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