Board Thread:False Info and Speculative Discussion/@comment-1487677-20160310214115/@comment-26879545-20160612110751

Mason was the host of Sebastien's spirit. Why would he go full strength when fighting Sebastien if he wasn't sure if it would damage Mason's body in the process?

Also, during the fight with Liam, he was being poisoned by wolfsbane for days before the fight. We've seen the effects wolfsbane has on (most) werecreatures. There is no way he would have been able to use his full strength, even if he wanted to. Not to mention he wouldn't have wanted to hurt his own Beta, so there's that. You may not want to see it, but there  are  reasons Scott doesn't go all out during fights.