Lumbers are constructs made out of trees with a giant club arm. Vanaduke is a giant troll of a boss who's possessed by dark magics and cursed fire, and he also happens to be royalty. They are nothing alike. Discussion over, end of story, bye-bye, see you later. :D

He's very obviously of the Trojan archetype. ...why would you think he resembles a lumber?

Vanaduke has a face!

The Royal Jelly has a face... in that he's a jellycube, and cubes have six faces.

Vanaduke is totally jelly. You jelly, bro?

All fiends are weak to piercing.

Lumber aren't fiends. Trojan are fiends.
Vanaduke isn't a Devilite, a Greaver or a Silkwing.
Vanaduke is a Trojan.

Vana looks sorta like a large lumber, dies like a large lumber...

but he acts more like a trojan with his attack(s) (when hes mobile anyway -- the mask stages are something else altogether)

His dad is a Trojan, his mom is a Lumber,
and he eats Jellies for breakfast.
Therefore, he is not one of these
but all three of these.

IGN The one and only, Guardianknight.

Notice that there are many Greek and Roman inferences in the Spiral universe, including GMs, so it stands to reason some of the lore is tied into Greco-Romano mythology.

The original Trojan Horse was the brain child of Odysseus, the mythical Greek king of Ithaca. Odysseus, known for his cunning, had his men craft a huge wooden gift horse made from pine lumber to hide in. Since the original Trojan Horse is a hollow vessel made of lumber, Vanaduke is a hollow vessel made of enchanted dark lumber to house the spirit of a long dead mythical prince or king. Since both Odysseus and the Gremlins are known for their cunning and construction genius, the Gremlins of Spiral Knights are the exiled descendants of Odysseus and Circe.

Circe is an immortal enchantress who had the power to transform men into beasts with her magic potions and enchanted flute. Some of the men were transformed into lions and wolves to guard her domain while her enemies were transformed into food swine. Thus, the Gremlins are the were-beast forms of the exiled descendants of Odysseus and Circe.

Odysseus had one son by Penelope, his Queen, and three sons by the immortal enchantress Circe. Penelope's son, Telemachus, eventually marries Circe, while Penelope herself is taken as wife by her own stepson Telegonus, who is one of the sons sired by Odysseus and Circe. Telegonus accidentally kills his father Odysseus. Odysseus believes in a prophecy that his son will kill him and take his Queen Penelope as with another Greek tragedy from Oedipus. Whoever deposes the King, takes the Queen as wife. What Odysseus doesn't know is that he has sired sons with Circe. Thus, Odysseus attacks Telegonus who is immortal thinking that he is Telemachus who isn't immortal yet. Penelope and Telemachus later become immortal when Circe takes them in. (Yes, Greek tragedies give me a headache too.)

Thus, the Lord Vanaduke mythos is one of those Greco-Gremlin princely tragedies that make your mind implode.

Or as the epic poet Virgil once wrote:
Timeo Danaos et dona ferentēs.
Beware of Gremlins bearing gifts.

Vanaduke is a giant Trojan with a few extra attacks.

a giant lumber weak to piercing..wooot, im on GL side~

He takes extra damage from vs Undead, does he not? (wiki says he does) Therefor, he is obviously a Giant Katt wearing a costume... What do you think the Katt in Moorcroft Manor is hiding, hmm? The dark ritual to control Vanaduke!!!

Lord Vanaduke is.... a Spy.

And he's sapping you. Yes, you. You're robotic and probably fired bullets at one point in your career. Ergo, you're a Sentry.