[@Suku]
I mean I was going under the assumption that any blow given we're Devils and this is dxd would be a powerful one. 

But I would say it goes like this.
Standard blows: 10 blows unless under special conditions or unless he has been given a boost in power somehow. 

Enhanced/powerful blows: 6 blows unless under special conditions or unless he has been given a boost in power somehow. 

Super blows: 2 blows unless under special conditions or unless he has been given a boost in power somehow. 

All attacks above super: about .5 blows. It MIGHT lessen the attack, but most likely the attack will break right through the barrier and he'll take the brunt of it. 

Sorry if it seems inconsistent or weird, never had to emphasize this type of limit because of how many variables play into it. But I tried to do each under normal conditions with no boost on power for Hakuryu or otherwise. Hope it's alright. And I'll try to keeps things in line as much as possible.