In my game, my players are most of the times in communication via mindlink since they are quite paranoïd about being tapped.
The question is to know if a decker in VR mode is able to keep communication by mindlink.
I've said no, as magic enhancement are not supposed to work in the matrix. (but now that i'm typing this, i realise i might have been wrong ...)

So this leads me to an interrogation : if it is truely impossible to "enhance" a logged in decker, than this means any mind affecting spell would be impossible to cast on a decker ?

If its possible to enhance a decker, than it should be possible to mind control him, possess him too, and so mage possessing a decker could cast spells on other deckers via sympathetic linking ?

Anyone has answers or suggestions regarding this issue ?

Ok long list here so:
Mink link yes, but the decker will be poor as he does not get a load of intiative bonuses.

The spells that enhance a decker for decking are in Matrix.

Other mind effecting spells can work on the decker if the caster has line of sight but are not that useful as he is in the matrix.

You can only possess a astral active character, it is i9n the meta magic description.

The former answer rules out the last question.

Matix active individuals can not cast magic via the matrix.