Serana can turn the player into a Vampire Lord and create Bloodcursed Arrows after being cured of vampirism.

This mod edits a grand total of 3 (count them, three) records, removing the requirement for Serana to have the 'vampire' keyword to unlock the relevant dialogue options, so it should be compatible with any mod, including those that change Serana, as long as they don't touch those records.

The alternative version should let her turn you into a vampire lord as soon as you meet her (the only requirement for turning is that you are not a vampire lord already), but it is untested, waiting for feedback.