Originally Posted by RBarbare
Yes, from a context viewpoint, but there are at least two other ways to look at it:

1:
The Absolute isn't a deity, despite what its followers think. There's a bit of dialog with Dror Ragzlin while he is trying to resurrect the mindflayer that shows what the Absolute is.

A circle of mind-linked mindflayers projecting their power through people infected with the tadpole.

So you aren't betraying your god for another; it's more like joining a rather restrictive club.

2:
It doesn't actually restrict your actions, e.g., you can still kill Absolute followers and do things your god wants. So it's a meaningless oath.

It doesn't matter if it isn't a deity yet. None of these deities started as deities - they became deities, notably three of them slaying a deity in order to obtain godhood. More importantly, you have forsaken your god. If you forsake your god for a being that isn't even divine then that being is not going to be able to protect you from the wrath of the previous deity and they certainly arent' going to grant you powers after you did so. The betrayal exists regardless of whether you did it for an actual deity or not.