"Vampire Lord"/"Hunter Lord"
    At max level after boss fight
    Not loose it
    Allow minion/recruit hunters
    Maybe one and only afterwards
    Different levels "Captain/Major/General..."

TODO: Reseach forum posts for more suggestions

Is this still a feature being planned?

Yes but many things have gotten into the way

it will great

Vampire Lord will come back? There was a boss in a special world before

It's been awhile since this was opened, will this be still feature soon perhaps?

Just some suggestions/notes by smashbro596:

i propose the lord form would have two modes: grounded and flying. while grounded, the lord gains a vicious claw swipe that has a lower swinging rate than a sword. in this mode, it can still bite, but it cant draw blood like the humanoid form can. in flight mode, it can gain some nifty magic abilities, such as grabbing enemies via telekinesis or an enhanced dark blood projectile. it can also fire a projectile that slowly drains a target of its blood. as a balance, the vampire lord form drains blood quickly unupgraded, and with insufficiant blood, you will be forced out of the form and cant re-transform until you drink the amount of blood necessary to transform again. its size isnt ideal for indoor environments. it also gets double the weakness to holy items.

Just some suggestions/notes by smashbro596:

i propose the lord form would have two modes [...]

Another proposal: Vampire Lords (VL) and Hunter Lords (HL) continue to have the ability to wear armor and use tools (insuring that on hardcore modpacks VL and HL are not a liability). VL and HL also have a dedicated skill tree as the players do.

Still looking forward to this after some years

So, just roughly 4 years later, this issue can finally be closed :D
The lord feature is implemented in the latest 1.7 alpha for MC 1.14
It allows you to control minions
https://gist.github.com/maxanier/1df3a7831ad2dd910df475ee99d48c25

It does not include the old "one and only" mechanic, but that might be an option in the future #757