I agree, there are plenty of bits and pieces in this kit that you could easily use for conversions. However, I think that since this is a
Terminator Lord you might find it quite difficult to use arms or helmets from this kit on a
power-armoured sorcerer/character, simply because the arms and heads of Terminators are slightly bigger/longer than the power armour ones. I don't own a Terminator Lord myself so I'm not 100% sure about this but I had this issue when I tried to give some
SM veterans Lightning Claws from the Assault terminator set. However this doesn't stop you from using the other, not termie specific bits (e.g. loin cloth, skulls, book...) or even cut the weapons you want to use for your second character off the terminator arm and stick it on a power armour arm. Otherwise you could definitely use the spare bits to easily upgrade a
CSM terminator squad if you ever were to buy one.
Hope this helps