Lightning strike
Lighning strike is a special ability of Thunderbirds. According to the game manual, every time a stack of Thunderbirds attacks (including reataliation), there is a 20% chance thunderbolts will strike their target, delivering 10x the number of attacking thunderbirds in additional damage. The thunderbolts have the same visual effect as the spell Lighting Bolt, and the special attack is also counted as one in terms of immunities.