Kalamax, the Stormsire, and Twincast

Prerequisites

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

Steps

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