We can't clarify if it's a bug or a real damage input... but i'm sure it's a REAL DAMAGE INPUT~! not a BUG~!
why would you spent 10 days of Hero run, if the card will just give 4.10 of crit...
there might be a hidden damage adds on.... or maybe if it's a bug it's already been 1 month i think....maybe a GM already acquired this sort of things.. and yet why not fixing it... so i guess it's REAL....
but don't take my word seriously... it's just that the heroic dungeon is so hard to finish/complete.... for me it's a reward...