I went through the DLC first, and it makes you hilariously overlevled. The bosses in the DLC are also overall harder, so you get really good practice first. Gehrman ended up being on of the easier bosses because of that.

Can't remember the exact number though... I wanna say the DLC was in the 80s range or something? Level numbers blend together a bit across the games.

I played the game at launch and finished the game just under level 50. He's kind of a push over, no matter where you come in.

I actually beat Gehrman on my second try. Yeah, the DLC really make you overleveled and you become even better at the game after fighting the likes of Ludwig, Orphan and Laurence.

Every time I play Bloodborne, I fall into a chalice dungeon hole, and come out of it over powered for everything in the game. I did that before the dlc and after.

I can't remember. Only recall spamming the parry, which seemed to work well enough against his lightning-fast attacks.