So I'm trying to platinum the game, I wonder what happens if you have three umbilical cords and you choose death when you talk to gehrman if you still get to fight the "true" boss if you ate the three cords or I need to play through the game another time to get that trophy.

@red_piano As long as you eat them before you kill him, you get to fight the secret boss and get that ending. It doesn't matter if you use the 3 cords before you refuse him, or after but then die and fight him later.

But if I eat three and then choose to die rather than refuse him, it just goes to NG+?

I believe you have to fight Gehrman to get the true ending.

You'll have to, without save file manipulation or whatever, go through the game three times to get the ending trophies. You can't get the final, final boss without fighting Gehrman and eating the Cords. If you eat the Cords and accept his offer, you get the accept offer ending.

Yes, you need to pick the refuse option to get the true ending.

Alrighty thanks fellows.

Couldn't you upload the save file to PS+ cloud save. Then take his offer. Download save, kill him. Download save, eat items, kill him and then move on for final fight/trophy? Or will it not work like that.