bat702 wrote:if you have a rule to reroll 1's or a hit roll that would normally give you a mortal wound, do you get to avoid the mortal wound?
These abilities only care about the final result of the roll. If you re-roll a 1 into a 2-6, it won't trigger the ability. Of course, if you re-roll a 1 into a 1, you take the mortal wound/get slain.
Keep in mind that Plasma is being changed to an unmodified 1 soon, so even if you have a -1 to hit, it won't overheat on a 2. Orks and T'au won't be so lucky for a long time, so will still hurt you more when shooting at blue eldar flyers at night.