This finale was a joke
The good guys getting close to defeating the master and then getting thwarted is fast becoming a joke. The first time in season 1, they really struggled and then we got this cool reveal that the master can survive sunlight. The second time when they decapitate him, they came close but still failed. The third time is kind of pushing it and it's making the master feel like a joke rather than this horrifying force.
I know the good guys are tougher than they were in season 1, but they just really steamrolled the master this time around and now he just feels like this annoying villain that just won't stay down rather than an actual powerful villain.
Also how many things had to go just right for that ending to take place? Eph had to get slashed meaning he got left behind (seriously, no one else got injured), Eph is the guy who got chosen to go along with Setrakian instead of Fet (leading to him getting injured), Nora and Zach got left in the building instead of some other location allowing Nora to head up and get ganked by Eph, the master had to choose to make Palmer his new host instead of just converting him into a vampire/drinking his blood and gaining his knowledge anyway (he couldn't have been doing this as part of his counter-ambush vs the good guys because he didn't know their plans), Palmer for some reason was stupid enough to tell the master that only he knows the master code and thinking that....thinking what exactly? How did he think the rest of the encounter was going to go? Zach had to be the one to hold on to the switch, the machine had to be unready (is that a word?) and Eph had to overpower Nora and not get bit at close range by her stinger. Oh and unlike in every other movie we have ever seen, despite it being the intelligent idea, they didn't chain the box shut even though Setrakian chained the other guy he chopped and boxed up at the bottom of the Atlantic.
A terrible and horribly contrived ending.