San’Layn feels incredibly proc dependent on the timing of the blood best to do any for of real AOE damage, as well as having very little visual to feel good or impactful when compared to Deathbringer or Rider of the Apocalypse.
My suggestion is to lean more into the vampirism and remove the randomness of the blood beast.
The idea is to change the talents Vampiric Strike, The Blood is Life, and Pact of the San’layn, this will also allow some re-allocation of damage through the tree for tuning to be simpler.
Vampiric Strike become Vampiric Pact, keeps all original details, gives you vampiric strike, but importantly now “Raise Dead becomes Summon Sycophant” ghoul is replaced by a vampire model.
Vampire ghoul replacement has same abilities as unholy ghoul, claw/gnaw/leap/huddle, but can be re-named, re-skinned. Vampire ghoul replacement also means for BDK when they go San’layn they now have a permanent pet.
The Blood is Life gets changed to:
“Each time your Vampiric sycophant strikes they store a portion of their target’s stolen blood. Every 10seconds they cause this stored blood to explode dealing 10% of the damage accumulated to nearby enemies and healing the Death Knight for the same amount” obviously % pending tuning.
Pact of the San’layn gets changed to:
Your sycophant can store 15% of all shadow damage dealt by you into the stolen blood increasing the damage when the stored blood explodes.
The thought here is both that there are many complaints about the aethetic of San’layn, in particular the blood beast, not matching the visuals of blood princes. And that by moving the damage from a proc that is very rare into something stable we add a solid asthetic look to the only hero talent missing one as well as easier tuning with less randomness.