the power of three

okay there was a lot of back and forth and cole being dead and then not being dead etc but in the end, he was going to give up his powers for her. I'm too lazy to explain so I'm just going to copy in these parts from charmedwikia

"When a Wizard attempted to become the Source, Cole allowed the Wizard to willingly transfer his powers to him. The process was stopped by Phoebe, who being manipulated by the Seer, vanquished the Wizard before the rite could be finished." --- "After stealing the book, he revealed his true desire to become the new Source and bring back his kind. He then worked with Cole to extract the Source from his body, but was vanquished by Phoebe under influence her unborn child and The Seer's manipulation. "

so don't you dare because cole loved phoebe, and phoebe loved cole. if it wasn't for the seer, they would probably be together in the end.