Issue #26193: Vampire Lord power Vampiric Drain lacks message to indicate reduced effect when Serana is a follower
As per the Wiki : https://en.uesp.net/wiki/Skyrim:Vampire_Lord#intnote_Serana
When Serana is following you, the Vampiric Drain spell's damage decreases dramatically. This is a result of a condition on the Damage Health effect of the spell; if Serana is following you, the Damage Health effect will be reduced to zero points for all levels of the spell.
The nerf is the original developer's intent, but this information is only communicated in script comments and never to the players, who often report the spell as broken in some way.
Add a sentence to the power's description in the form "Damage is reduced while Serana is your follower."