first off, as anyone can tell you, power levels are BS. Second, there actually are anime for P3, 4, and 5 if you want to check those out. As in most series its kinda impossible to give a real estimate of strength for their fantasy aspects as they tend to be pitted primarily against each other, and thus no real world measure can be accurately used

It's not really about sheer power, more so that in story a personas strength doesn't come from just being powerful. Rather they're mental constructs formed of the summoner's will and mind. The exact power levels of Personas also aren't very relevant to any game or adaptation though. So in the end it's a question with no real answer.

Strong enough to probably kill you, depending on the exact persona, maybe in one shot

If the gun rule applies to them, then they're just as deadly as they look.

If the gun rule applies to them, you can slaughter anything with wings.