With pleasure
The Old Gods, created by the Void Lords, corrupted a nascent titan and tormented it until Sargeras put it out of its misery. As shown in the heading “Star Augur Etraeus,” we can see that the Void likes to attack worlds in the same way the Legion does. There are three shown during his raid fight.
Here we have, in classic fashion, the Void trying to destroy a world that a Naaru saves. By sacrificing his own life.
This planet, the home of the Ethereals, was attacked by the same being as the previous link. Dimensius the All-Devouring was one of the Void Lords who managed to enter this reality.
The Ethereals weren’t as lucky as Karkora.
Probably one of the best known villainous groups in WoW history, simply because of how prevalent it was.
Twilight’s Hammer tried to destroy the world, that is literally their only goal. The people who joined were driven insane by the void.
Since I’m anticipating you might still use the Lightbound in your arguments, it is therefore worth going ahead and offering a counter to it early.
The AU Shadowmoon Clan was pressured into wielding the Void, and it then corrupted them. They raised the dead, defiled their ancestral graves, and tried to massacre the Draenei through the void.
Nether-Prince Durzaan is the corrupted Ethereal who tried to forcibly convert the Void Elves into slaves of the Void, but was only able to get it half-right thanks to the hero’s interference.
A very deadly Old God, he is an example of the Void’s evil because of what he was able to accomplish even after death.
His Sha (the vestiges of his existence) terrorized Pandaria until the Emperor taught his people how to conquer them.
His heart later corrupted Garrosh Hellscream and transformed him into a murderous raid boss.
Though his death was underwhelming, N’zoth has done more damage to Azeroth than most of the other Old Gods.
By his whispers did Deathwing go insane and trigger the Cataclysm. Which means the utter destruction is the Void’s fault. More importantly, we all get to blame N’zoth for creating the circumstances that made King Magni a crystalline man shouting about “WOONS!”
He also tainted the Emerald Nightmare with his servant Xavius, and thus is responsible for the death of Ysera as well. As in, N’zoth has participated in the downfall of two Dragon Aspects.
C’thun’s work is moderate compared to N’zoth, but still of note. He rallied the Qiraji and sent them in a vicious assault on Kalimdor, that was narrowly stopped during the War of Shifting Sands. Then there was his return in Vanilla.
Yogg-Saron brought down Ulduar and left Azeroth’s defenses greatly compromised in the event of an attack. Many big name Titan constructs are dead because of him.
More noteworthy, he caused the Curse of Flesh that affects humans, vrykul, dwarves, gnomes, etc.
A little bit trashy by the comparison of his full Old God kin, G’huun brought about the near downfall of the Zandalari.