Board Thread:False Info and Speculative Discussion/@comment-4705573-20160408003331/@comment-26879545-20160410133920

^ It's non-canonically called "homocidal absorption." I say it's a non-canon name because, IIRC, they didn't name the process on the show itself.

An Alpha that kills their beta adds to the Alpha's power (ex: Deucalion and Marco(?), Derek & Boyd). It seems that they don't have to go through the Pain > Life > Power routine when it comes to their betas.

Now, this is all speculation, but, if they were to try to steal another person's power, they (logically) would have to go through the Pain > Life > Power cycle that Deuc taught Theo. I would assume the process time varies between person.