The Thrull from #mtg as a #dndnext monster

Thrulls are strange creatures that have evolved through a variety of forms and functions along with the game, in Magic: The Gathering.

As a game/bet with @ArtificerAlf aka Karl Rech, I wanted to create a creature for our Ravnica D&D Next campaign, and I let him name the first one. He chose Thrull.

The Concept

In Ravnica, the Thrull has no defining ability, if not perhaps the one of the most common type, Regeneration using Black mana.
In previous expansions though, Thrulls were actually more similar to each other and shared a common theme of giving either Black mana or some kind of bonus to other creatures when sacrificed.

The general feeling of the Thrull is thus that of a un undead-like construct, infused with dark magic, and at the service of Clerics or Wizards of White and Black alignment.

Taken from The Return of Thrulls

I decided to translate this into D&D terms with some kind of "switch sides" potential, connected to magic.

The Base Creature

After a quick search that ended when reaching the letter D in the Bestiary, and in particular at the "Demon" entry, I realized that the Mane demon had all the base requirements: a somewhat lowly creature with a strong arcane nature, that dissolved when killed (dissolves in Black mana perhaps!) and reforms somehwere else.
Now how to tweak that...

The Tweaks

I definitely want the Thrull to be linked to some specific spells. In particular, I think the Cure Wounds / Inflict Wounds would represent very well the White/Black duality of Thrulls, and these spells could basically help the Thrull retake form. Instead of completely dissolving, the killed Thrull would kind of "lose pressure" and leave a husk and a cloud of dark energy/vapor. This cloud can be manipulated with these spells to reform the Thrull. Also, since it's always Black mana to regenerate, I think I will limit this to Inflict Wounds, but I also want a Wizard spell to be capable of doing the job, although at higher level. This way the link with the clergy is more prominent, but a possible link with Wizards would not be impossible. An iconic necromantic spell to be used for this kind of work could be the straightforward Animate Dead, two levels higher than Inflict Wounds and its undead-curing capabilities.

Returning to the initial concept, we could make the reformed Thrull be charmed by the one casting the spell, thus representing the "switching sides" potential that kind of makes for a truly "quasi-construct" creature. This, in addition to the Immunity to Charming, makes for a special kind of servant, who can't switch sides unless "mana" is used by the wanna-be master (and only after it has been "killed").
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Eternal Torment (Thrull): A thrull reduced to 0 hit points or fewer emanates a cloud of black vapor, leaving behind a flaccid empty husk. The cloud moves in random directions for 24 hours at a speed of 20 ft. before dissolving. If the thrull's body husk lies within 20 ft. of the cloud, casting Inflict Wounds or Animate Dead on it brings back the Thrull after one round, and charmed by the caster.
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As for other resistances, I think the Fire resistance is a bit off, and I'd replace it with Necrotic resistance. The other ones I think they make sense, Electricity being in theme with the pseudo-Frankenstein-esque nature, and Cold being usually resisted by undead and constructs alike. I'd also add Poison, just out of consistency
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Resistances: The mane is resistant to cold, necrotic, lightning, and poison.
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Attacks should be ok, although Thrull could also wield weapons, making them a bit more dangerous.

As for the creature type, I think I would stick with Construct instead of Undead, so that Rebuke Undead doesn't overlap with the integrated method of making the Thrull switch sides. So it would be a Medium Construct (Thrull). Perhaps Living Construct if that becomes a type.

Additional "Kit" Ablities.

Called "theme powers" in D&D 4e, a menu of optional abilities can make for a really customizable creature.
I think I would give Thrulls three of these, to represent the coolest Ravnican Thrulls.

First of all, a larger Thrull (with base statistics and special abilities of a Hezrou demon, but with the same tweaks described above), could have a Consume ability making it able to represent the Maw of The Obzedat thrull. I'm also adding a restriction on the Thrull's movement, to represent this big fat guy:

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Consume:

A Large Thrull with this ability can consume a helpless creature, or a creature it has killed with its Bite, and transform it into necromantic power, giving selected creatures within 50 ft. benefits equivalent to a Prayer spell. Not being originated by a spell, these bonuses stack if the ability is used again, and they only end if the Thrull dies, moves more than 5 ft per round, or if the subjects leave the effect radius.
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Another interesting ability to be converted is the one of the Thrull Parasite. Let's see what I can do:

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Parasite:

The Master of a Thrull with this ability can choose to suffer 1 Hit Dice + Con mod of damage to make the Thrull cast Dispel Magic on a selected creature, object or location without expending spell slots. The dispel roll is made as if the master had casted the spell.
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Finally, a Thrull can have the Extort ability, maybe accompanied by a single 1/day usage of Sanctuary to make the most out of it. You can find the conversion of this mechanic in the Orzhov entry of my conversions of Ravnican "Guildmages" (as D&D Next Clerics) here.

Another final option for Thrulls could be functional wings, giving it a fly speed of 20 or 30 ft.

That's all folks!