Problem translating camera rotations to blender

I understand this question may push the limits of being a cesium question. I am working on a project where cesium is being use for a UI to generate a camera path. The only problem I have in getting this to work is the translating camera rotations.

The values in cesium is not matching up in blender. for example

(x,y,z,w) = (0,0.707,0,0.707)
Cesium = Look = down with up = north
Blender = Look = west with up = north

blender values to match cesium
(x,y,z,w) = (0,0,0,0.707)

(x, y, z, w) = (0, -0.707, 0, 0.707)
Cesium = Look = to sky, up = north
Blender = Look = east, up = north

blender values to match cesium
(x, y, z, w) = (0, -0.707, 0, 0)

In blender i am using a equi-rectangular projection with
(+)z - up/altitude
(+)x - east(lon)
(-)y - south(lat)

Is there a function in the cesium API to get the rotation values in the local coordinates of the camera object iself. I can work with euler rotations as well, providing i know the order of the rotations.

I was hoping to find a pattern that i could just design a conversion but with my tests thus far i am not seeing a way to convert.

Any thoughts would be appreciated.