Vampire Orc Prep

Other night a lady asked me what are you dreaming of?
This was a bit awkward but here it is:

In my campaign in Chagrinspire players annoyingly made friends and truces all the time. They even freed kobold slaves and took them to some kobolds they fought once to make peace stronger. So when you design a 200 room dungeon and players just make friends it's a bit of a sigh moment. So I was keen for beef to erupt at an inconvenient moment. I hoped players would cheat the orcs somehow but they didnt.

So party have a deal with orcs who get half the treasure and pick of magic items for access to Chagrinspire. The party found an experimental lab possibly used still for strange artefacts and party took a bunch and the orcs took 3 items.

A crystal fallen from the sky (GusL stylecrystral adventures) the orc magicians broke and huffed crystals and infected - a wizard and priest. 

A prehistoric vampire head, one of the first generation predating humans.

An alien evil tree seed has also fallen from the sky grows into an intelligent evil life-staying tree.

So now divination, gossip and rumours talk of a change in the orcs.

They now wear the sign of a tree with a screaming evil face on their chests, sheilds and banners. Now they worship the Bloody Tree an alien evil plant now also a vampire, they sacrifice victims by tying to the tree which drains their blood with thorns.

Cheif Kudokan the new leader
LE Vampire
AC +9 HD 9 (68hp) Att Sword d8+4 or Bite d6+2 + 2 levels drained 
Morale 11 Mov 12 (spiderclimb) or as Boar 18 or Bat 24 or Vapour 9 
-Requires holy, silver, fire or magic weapons to harm, regenerate 2hp per round 
-Repulsed by holy symbols, running water and strings of pork sausages
-Sunlight, fire or a steak through the heart and decapitation stops regeneration
-Can assume gaseous form and can escape or avoid physical weapons to heal
-Boar form faster and charge att: tusks 4d4+4 (double with 9m runup) + 2 levels drained 
-Bat form a single giant bat or a swarm of bats, can use wings in humanoid or boar form
-Rat form a single giant rat or a swarm of rats 
-Hypnotic gaze instead of attack while humanoid, save each round or stand dazed and miss an action for a round, if it lasts a second round the victim drops anything in hands
-Can control 9HD or rats, pigs bats or any combination even swarms, some might save to resist if unusual or a pet of someone else
-Can create a thrall by drinking and feeding blood for three nights often using hypnotism

Thralls of the Bloody Tree
LE servants of the vampire lord and the Bloody Tree
AC +6 HD 6 (40hp) Att Sword d8+1 or Bite d4+1  Morale 11 Mov 12 (spider climb)  
-These thralls are on the path to vampirism and obey their chief and
-heal 1hp per hour if they drink the blood of a person or animals of equal mass daily 
-Sunlight hurts eyes -2 actions using sight and initiative

Boars of the Bloody Tree
NE transformed beasts
AC +4 HD 3 (14) Att tusks 2d4+2 (double with 9m runup)  Morale 10 Mov 15
-males are berserkers if they reach zero HP, can fight conscious to -10, +2 hit & damage
-two can pull a chariot AC+4 HD 4 (18) Mov 15, driver a hero and an archer for crew
-can carry an armoured orc into battle, sows carry lighter armed female or young archers
-eating their flesh can infect the eater with the berserk condition at 0hp if fail a save

Orcs of the Bloody Tree
LE transformed orcs
-Skirmisher AC +3 HD 1 Att shortbow d6 Morale 9 Move 12
wear leathers and carry a light weapon like javelins or shortsword or club
-Warrior AC +6 HD per Lv most 1 Att by weapon Morale 10 Move 9
wear scale with shield and carry a spear and sword or morningstar mace
warriors fed on special boar meat to make them all berserk at 0hp
-Hero AC+7 HD 4d12 Att by weapon +1 Morale 10 Move 9

This also will buff the basic orcs

I guess dnd5 has vampire trees as a thing but this was an organic fluke event it could have been vampire turnips or a crystaline tree