Doom Mantis is what would result if a Doom Blade were to go to a sort of dojo to hone it's skills and control it's strength; It converts from a sort of brutal, dirty, and self-harming berserker frog to a calm, cool mantis capable of dealing low EN damage with no recoil.
Other than cheap damage, Doom Mantis's long, stabbing appendages are capable of piercing ARM and, with a Yellow Spike boosted Flay, the armor is peeled off the opponent painfully! That's a vivid image I don't want imprinted in my mind. Or my skin, frankly.
Possible evolutions include: