By spells you are meaning source spells right?
UMM all spells in the divinity universe are source spells because source is the mana needed to cast the spells, eliminate the mana, and you render a mage useless.
Because collars don't prevent you from casting any other spells but source based ones. So as long as they don't cast source spells, it's perfectly valid for them to use normal ones.
In the divinity universe there is no such thing as "Source Spells" All spells are source spells. Again Source is nothing but the mana required in order to be able to cast any and all spells.
In the Divinity Universe .. "The Source" is the power in which give the ability to cast any and all spells in without source at your disposal..spell casting of any kind is not possible. The collar in this game is the equivalent of putting a constant mana drain collar on a mage in Skyrim. Without mana, a mage cannot cast spells, and just like that without source it's impossible to cast spells.
You just completely contradicted yourself, and the game because you failed to read and or comprehend what you read as well as understand how the universe in the game works.
