Corey
This is honestly a rant but Corey sucks!!! Towards the end of season 5B Corey was really upsetting me when it came down to his decisions with Mason.
While kissing Mason he discovers Mason was the beast then proceeds to tell literally no one about it. You can say ok well he lost Mason at the game and was trying to find him. That's true and fair but when he finally finds Mason it's when Scott and Liam are digging through Mason's trunk and they learn/tell Mason he's the beast. Instead of like being there with Mason and getting help from Scott's pack to protect him from the dread doctors and come up with a plan to save him, he chooses to uncamouflage and take Mason and run and hide in a sewer.
I found this to be the dumbest decision ever as the dread doctors already proved to Corey that they can find him no matter where he hides even if he is camouflaged!!! Mason had to remind him they can just use frequencies to find them and guess what they did they found them.
That one dumb decision lead to them not knowing where Mason was which forced them to waste time finding him!! Instead of spending that time solely to figuring out how to save him instead. Worse part was the dread doctors used Mason as a lure/trap for Scott, Theo and Liam and it lead to Mason being lost and fully transformed into the beast/Sebastian. This for story purposes would've still happened but at least they could've been able to fight against it more since the Dread Doctors would've had to fight off Scott's whole pack to get to Mason instead of just scooping up Mason under a bridge.