I vaguely remember something about Ashnard's armor being blessed but not sure about his Prf sword. If it wasn't, BK takes it easily.

But Ashnard doesn't take it easily if his sword is blessed.

BK has 48 ATK, 20 AS and 30+5 DEF

Ashnard has 55 ATK, 16 AS and 35 DEF

BK can double Ashnard for 13*2 = 26 damage per round where as Ashnard deals 20 damage per round. Both BK and Ashnard has 60 health and Renewal so they'll both heal for 6 HP each turn. BK effectively does 20 damage a round for a 3RKO while Ashnard does 14 for a 5RKO

The interesting thing comes from HM/Berserk Ashnard.

HM Ashnard has the ATK of 60, AS of 17 and Def of 35. So now he does 25 damage per turn and BK only does 13 since he can no longer double. Ashnard's HP also increases to 80 so now he regains 8 HP per turn via Renewal. So now HM Ashnard effectively does 19 damage while BK only does 5 damage. HM Ashnard can 4RKO BK while BK needs 16 rounds.

So you'd think BK's only hope against crazy Ashnard is his Luna right? Nah. PoR's Luna activation is SKL% and BK's got a hefty 30 SKL. If BK procs Luna, then he'll halve Ashnard's DEF to 18 and deal a whopping 30 damage. Or 22 with HM Ashnard's Renewal. Assuming he always procs Luna, he'll be able to 4RKO him. But there's only a .81% of that happening.

TL;DR: BK will kick Ashnard's ass all over Tellius but HM Ashnard will kick BK's ass everyday of the week and twice in Sunday.

Watch there be a minor math error in there and completely screws things up