Of course Larian's choice of load screen shorts may be the biggest tell.
Specifically the bit that Tells you about Bane, Ball, and Myrkul.
This is also refereed to in the Book of the Dead God's, You have to pass checks to read, as if Larian wanted to put weight on this information.
Finally the loading screen infomercial also mentions Jergal.
In conclusion we were a Baal Spawn in 1 and 2, and now, years latter, the same dark forces are rallied for another go at ignoble designs.
Mwaa ha ha.