I bet if you checked the walkthrough, you could find the answer there.
SWC
Sir Edmund:"Should you obey the lord who asks you to put a village of innocents to the torch? Is that chivalrous? Is it noble?" Me:"It's a great way to get promoted, I know that much."
well if you're in the Naga Temple you're in the right spot. lol There's a room in the Naga Temple with a ramp with two small closet like rooms. When you enter the room you'll be bombarded with alot of snake like opponents when you defeat them all get on top of this ramp and you'll see in one room with a healing fountain the other closet like room has a key. This room is right around the the corner from the fire room where the fire is coming out of the floor. Good Luck cause I thought the Naga Temple was one of the hardest areas of the game.
Thanks to SWC advise on the walkthrough, wich i didn't know existed, i made it to the Shadow Ruins and having now a hard time jumping those evading blocks (only four) to get in time to the shadow gate on the other side.
i guess retries will finaly get me thru LOL