How do you actually use quaternions?

I'm trying to make an object rotate in real time, locally, dependending on the local rotation or position of other objects

Wire parameters is not quite doing the trick, so I believe that the solution might be to assign the RotationScript controller directly replacing the default Rotation:Euler XYZ, instead of just creating scripts inside the Rotation:EulerXYZ>X_Axis, for instance.

The problem is that's in quaternions

I watched the advanced "Matrix Explanied" videos, but it still elludes me how to actually use it. Is there some examples on how to use full quaternions if I replace the default Rotation:EulerXYZ by the RotationScript controller?

Thank you very much

- Nelson Baietti