o.k.,please, where do you find the holy water for kerah? do you use a flask? i also killed both champions and had the keys, but the door in lava room wont open? i have the amulet from the ledge, but it ain't opening? now i don't have the keys,oh what to do,pleasssssssssssse?

No panic. The keys have served their purpose. The door only opens after you've freed Kerah. You just need to fill one of those empty flasks in a pool of holy water close to the entrance of the pyramid. It's a fairly large room with the pool and a fountain on one side, and on another something that looks like a temple entrance, complete with two clickable, but worthless guardian statues (lion-like).