Actually, the comics take place BEFORE the game timeline was. I mean, he had to be Teneb Kel first before being Darth Thanaton in the game.
Indeed, Teneb Kel in the comic is MUCH younger than Thanaton in the game. The comics are a prelude to the game.
ps. Blood of the empire is one of my favorite Sith comics of all time, I absolutely love it and acquired it as a hardcopy too.