Ok I have no idea what to do with Holy pedastal, I have found ashes and the small figurine that raises me up but it only raises me up into water filled place so I can drown, big time help needed.

As soon as you ride up the pedestal into the water, look for a switch on the wall. Flip it, then swim as fast as you can for the top. The roof will open (you'll get the "Loading" message) and when you break through the water, you'll be in Kerah's temple.

Sazerac.