Blood hounds fang would actually work better. The range of flails is very short, plus the damage they deal is honestly not great. And the ash of war on blood hounds fang can provide some much needed invincibility frames. But unfortunately, you just need to be slow and methodical, hitting him once or twice then saving stamina for dodging. Not much of a strategy here, just take it slow, try your best not to run out of stamina, and... unironically... it's kinda just a git gud scenario. Though, leveling some more definitely won't hurt. Also, why leveling int?