I find it hard not to point out the irony in OP's name. Perhaps a part of the troll. Alas.

4 AR - Original Sin

Quote
Sadly I must confess that once more my knowledge about these long forgotten times is diminutive at best. Very little is known about the strange and spectacular events that befell two so-called Source Hunters. Nevertheless, if one can put faith in the fragmented stories told by old wizards, they both prevented and set in motion events that changed the destiny of fair Rivellon herself.


- Divinity Wikia

Refers to Source Hunters (Which is what you were in Original Sin 1), and they could use magic. Which would be an even bigger overlook if they had used Source too. But the oncoming void had weakened and corrupted Source so they couldn't use it. Yet the classes had spells and magic like any other, which the Source Hunters could put to use in their hunt for Sourcerers.

This history is written down by wizards.

Source spells wasn't a thing in Original Sin 1, completing DOS1 cleansed Source to be used and thrive once again, hence a thing in DOS2.


Coughs. Definitely troll post.