Corrupted blood

hello,

I play RF and have a qustion about a mechanic. In the tree above "prismatic skin" the guy who made this build picked "corrupted blood can not be inflicted on you" but he also picked Ralakesh as a minor god....who has as upgrade also corrupted blood. Am I missing something or is this a bit strange pick?

THX

The upgrade of the Ralakesh pantheon soul still allows 5 stacks of corrupted blood to be inflicted on you.

If you get immunity to corrupted blood, the upgrade is not necessary, but it can still be worth picking the soul for its base benefit.