Losing all teammates.
"Well, he's all alone now, maybe he'll stop being such a dramaaaaaaaagh..."
Last Mohican is an unlockable passive Ability. If the Trooper with this skill is the last living (or the only) trooper of their wave then he will automatically empty his clip and double his Damage at the enemy's he fires at.
Quite rare ability to see used in the field. Bearing similar dangers of misuse as Nervous, it's crucial to have enemies closely packed for best results. Facing spread out hostiles, emptying the clip while the damage is doubled is not always necessary, especially when the former is almost full. And so, weapons with minimal capacity benefit from only double damage, not suffering from the risk of burning through all the munitions in one burst. Last Mohican apparently applies to punches as well, replay.
Note: This skill cannot pairs with Crybaby as the action will make Last Mohican totally useless, unless the trooper is the last survivor of last wave.