Spent about an hour grinding to get my strength up enough for the Greatsword only to discover that it's absolutely fucking awful. Not enjoying navigating Stormveil castle either.
Honestly I'm starting to think I'm reaching my peak with the game, but I thought that with Margit before finally slaughtering the cunt. Might see if I've missed any dungeon bosses to tick off before giving Stormveil castle another try.
Did you clear out Castle Morne yet? There's a blind girl near the grace before you get to Castle Morne who gives you a letter to give to her dad, who's the commander of the Castle.
You can find him sitting on a bench on one of the Castle walls, towards the back of it. He won't leave until you fight the boss that's on a little shallow island behind the Castle, he's one of those winged Misbegotten creatures that you fight all throughout the Castle, only he's much bigger.
After you kill the boss, talk to her dad again, he'll give you some big weird sword, but that's not why I'm telling you this. After that, go to where his blind daughter was by the Grace on the way to the castle, and kill him.
I'm pretty sure his quest is over with and there's no repercussions down the line for killing him, but double check if you're curious
He drops a +8 halberd that's pretty badass. I wasn't a big fan of it at first, but it was so strong compared to my other weapons I kept on using it and got used to the way it handled, especially on horseback. It's like a combination spear/axe.
It might make Stormveil Castle a little easier for you. I wield it with a shield.
Also in Castle Stormveil, I think it's called the Rampart Grace, you can go downstairs right near there and fight a lone Banished Knight. You can keep going back to the Grace to respawn him and eventually get his suit of armor. It takes awhile since he's just one guy, but the armor was quite a bit stronger than what I was using previously (The knight set sold by the two headed thing in Roundtable Hold)
It is pretty heavy though. There is a tailsmen that lowers your encumbrance but I don't remember what it's called or where I got it.
Oh, a tailsmen you should definitely try to get before you finish Stormveil Castle in the one outside the Beastial Sanctum in Caelid. Warp there from the third church of Marika and take a right when you exit the sanctum. If you have online turned on, there should be notes telling you where to jump down.
Make sure you spend all your runes first because it's a lot of trial and error when jumping down and you'll die a lot before getting all the way down there. The tailsmen you find is worth it though.
It raises your defense. It was a big help.