I'm stuck in shrine :
- I managed to make the ray of light go on the main altar, but I can't find Anephas ashes !
- I can't go through the stairs which disappear when walking on them (just next to them is an alcove with monkeys drawings), tried every objects I have, nothing does
- There are two doors I can't open :
- the first behind the fallen column
- the second deep in the shrine, there are two stone faces in the wall, and a sort of door in the middle

really stuck here...
I will welcome any help !!!
somebody told me I need a joint monkey... where can I find it ?

Well you were certainly on the right track there!
You need to find a double monkey idol - sort of a bridge like thing - which you will place in that monkey alcove (you had it figured out just didn't have the object you needed). It is somewhere in that pyramid. I'm not back at that point in my second replay so can't help too well with it's location - maybe in a chest in one of those room you either have to fall through or try to jump across without falling through.

The door with the fallen columns will be the last door in the pyramid that you will use - that one takes you to the second sea area but you've got to get the monkey bridge idol to get further.
If I have any brilliant flashes of memory, I'll repost but hope this gets you at least motivated to continue your own search!

Wyv

I am only slightly ahead of dagnar and also stuck in the sphynx temple, unable to continue to the other side. I can't find anything of value in the room with four stone buttons and a moveable obelisk center platform. There must be a trick here, I can see small holes, can even jump up to them, but nothing appears when I push all the buttons. Surely this room has a purpose beyond spawning critters. I have Anephas ashes, what object do I need for the light beam pillar? I know about later moving the small gold obelisks to deflect the light path. This may be a dumb question, I may already have the item since I have explored about everywhere (killed the Darkened One and returned the Holy Relic).

Keep playing with the sliding scarab buttons in the area where you found the Darkened One. You will find a big room with running water and a shrine that slides into the floor. In a chest nearby is an idol, put it on the shrine and a big pillar rises out of the central pool taking you up to see kerah. The stone of light is there.