Update 1
Just tested the power of impalement and the result was unexpected.
imgur link for bigger pictures
http://imgur.com/a/Vv6NRI'm not even sure what happened here, but it seems like on top of the already high base damage of impalement, the oil being lit up caused surface fire damage
twice to each of them, but where did those crazy magic armor damage numbers come from?
Fireball
Spontaneous Combustion
Killed pretty much all of them with 3 skills, something is wrong with oil interaction with fire and aero bonus it seems, I shouldn't be able to do that much magic armor damage.
Conclusion, even after the magic armor part gets fixed, impalement still looks extremely strong with the high base damage and oil causing surface damage twice.
However I fail to understand why fossil strike cost the same ap as impalement, doesn't have crippled status, (which is weird to begin with considering impalement deals magic damage and crippled is a physical status) have less area of effect than impalement, and deal less damage than impalement, the cooldown difference of 1 turn is pretty pointless when skin graft exist, there is the same issue with searing daggers vs fireball, the power level gap is simply huge. Perhaps there will be changes in the future.