Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - General How to kill winter dragon in a turn.

I was wondering what the winter dragon drops, so I made a party for it. A naked lizard that attracted dragon's attention so my backline could invis, and killed it in a turn.

It seems like my crits weren't affected by crit multiplier, or used only the main hand weapon, might be a bug, my character has 40 tooltip damage on character sheet, and 155% crit multiplier, 5 points in warfare, used mortal blow while invisible, in theory I should be hitting for 40 x 10 x 155% x 1.5 which is around 930 damage, but I only did about 600 damage each mortal blow.

Imgur link for bigger images.
http://imgur.com/a/HpTVH