I am a ranger and am having trouble deciding if I should take the feat imrpoved critical slash and use 2x +3 flaming burst kukris or stay with +2 holy burst SS, +2 holy burst rapier. I don't have the feats to swap out for oversized TWF and I know the crit range with kukris is better and I would crit more but a lot of things in mod 6 are immune to fire and everything seems to be evil. So I'm asking for some advice, do you think the kukris are more dmg on mobs that aren't immune to fire compared to holy burst on the same mobs?