can you do the usurpation of fire and the end of fire endings both in one play through?

[violet tide]

Going for the platinum

I've done all the steps for the usurpation ending but I didn't know if doing the steps for the end of fire would mess anything up

[dry pollen]

you do one ending at a time

if you want platinum, you'll need to beat the game multiple times anyways due to boss souls sometimes offering multiple spells
Not to mention the all rings achievement requiring NG+2 (assuming no cheating)

[left jacinth]

You can complete the steps for multiple endings in one playthrough, but you can only choose one ending at the end