I got this the other day and noticed the weird mod. I looked it up and found out that this mod is not available as an inscription so I was wondering what this is worth:
Fellblade
Slashing Dmg: 15-22 (Requires 9 Swordsmanship)
Damage +15%
Energy regeneration -1
q9 Fellblade (mod not available as insc)
kousei