In the previous system, killing/sacrificing a human or one of the other god's followers was part of the adept requirement. Therefore, we will be using whichever method your character chose then to place them at Tier 2 on this system. However, if your character has continued deliberately serving their god in other, noteworthy ways, these acts may be used to promote your character to Tier 3.

In short: as an adept he would default begin at Tier 2, regardless of who he killed to get there, but if you provide evidence of other works done for his god beyond his adept-qualifying kill, he may be placed at Tier 3.