Heinrich Kemmler vampire counts warhammer 8th edition special character overview
In the game
Heinrich Kemmler is a special character who is effectively an improved Master Necromancer. He is slightly better in combat with a weapon skill, strength and initiative of four combined with the two bonus attacks from the chaos tomb blade. Although missing from the 7th edition book Heinrich is an old special character who along with Krell is making a return from an earlier edition of warhammer fantasy battle.
Heinrich has the lore master (lore of the vampires) and master of the dead special rules. Master of the dead allows Heinrich to increase the unit size of skeleton warriors past there starting size. If you have Heinrich no other necromancer or master necromancer can take master of the dead.
Heinrich carries three magic items that are unique to him as a special character. These are the chaos tomb blade, the cloak of mists and shadows and the skull staff. The chaos tomb blade increases his attacks by two and allows him to raise either a skeleton warrior or a grave guard for each model that he kills in melee combat. The cloak of mists and shadows either grants Heinrich the ethereal special rule or allows him to fly. The skull staff grants Heinrich a plus one to dispel it also forces your opponent to to reveal all magic items within 12" and who is carrying them.
Pros and cons
Pros are lore master (lore of the vampires) giving him every spell that you will need to keep your army intact and fighting at maximum efficiency (and a couple you probably will not use). With the ethereal rule from the cloak of mists and shadows he can also be difficult for some armies to kill particularly if lurking in a unit with Krell the lord of undeath.
Cons are that Heinrich is a little bit on the expensive side for a master necromancer and although better in melee combat then a normal master necromancer he is far from the combat prowess of a vampire hero. Also melee combat is probably the last place you want your high level wizard although the cloak of mists and shadows combined with the skull staff can help keep him safe. Heinrich also comes on foot and no mount upgrades are available for him, whilst he can use the cloak of mists and shadows to fly this in turn means he loses the ethereal special rule leaving him vulnerable to war machines and shooting attacks.
The cloak of mists and shadows ethereal special rule varies in effectiveness depending on what enemy army you are fancy daemons of chaos and wood elves have troops with magical attacks and will soon tear him to pieces in melee combat.
With lore master of the lore of the vampires Heinrich Kemmler gives you a way to get more spells into your army (Mannfred von Carstein also has this trait) this can particularly of use in larger points battles. The skull staff is also useful for armies with a lot of ethereal troops as it reveals which enemy characters are carrying magical weapons and can harm them (and therefore Kemmler) and plus one to dispel also comes in handy. Being ethereal from the cloak of mists and shadows means Heinrich is much less likely to die from the attack of rank and file troops as only a few have magical attacks and can harm him.
For a pure spell caster in smaller points games a master necromancer can be a better choice and you can easily tailor his magic items to suit your play style. In bigger points value games is where the benefit of Heinrich Kemmler's lore master special rule comes into play.