Variphor is an entity that existed somehow between the worlds; between "existence" and "non-existence". It was discovered by the Yalahari in their quest for knowledge. Originally unbeknown to them it had vicious nature, however, and soon the Yalahari's discovery turned against them; manipulating them into killing each other one night, when most of the them were killed. The rest then fled their island, which was left to their former minions. It is unknown what became of Variphor, but rumours tell of one of the Yalahari who returned, now under the influence of Variphor, to cause destruction once again in Yalahar.
As an attempt to fight Variphor, some of the Yalahari sailed to Gray Beach. Their plan was to use the Insectoids there as an army to kill everyone in Yalahar, and the existence of Variphor with them. Despite their initial success in creating this army, the research team is constantly being attacked by native specimens, as well as suffering from treachery among themselves. Ultimately, the lead researcher becomes completely paranoid believing Variphor is sabotaging its mission and the entire team perishes when the backup they requested doesn't arrive (by this time, the city of Yalahar has already been taken by the evil Yalahari).
Variphor is also most likely responsible for the demise of Roshamuul. The island used to be under the control of followers of Zathroth, until these followers realized there were traitors among them that had defected to (...) a third power, as told in The Dreamers IV (Book). The Roshamuul Prison was built to lock these traitors, but only one Prince was caught before a major fight begun, which led to the destruction of Roshamuul. This imprisoned prince is most likely Prince Drazzak, whom yells "VARIPHOR WILL RULE!" while fighting.
While trying to stop Ferumbras' ascension to godhood, the players are betrayed by Mazarius, who steals the parts of The Godbreaker, and we learn that he is working for Variphor through an unfinished letter he left behind while escaping.
After that, the Messenger of Heaven tells us that the actions of Ferumbras and the sinister minions of the thing from beyond have shattered the world. About this thing that is entering our world, it also says that To name it is to give it power and that the ancient Yalahari were the first to really grasp at least part of the concept of what it is. All this points to Variphor, even though the Messenger does not mention its name directly, but clearly intentionally to avoid making Variphor even stronger. The messenger reveals that to stop them from devouring reality, the destruction has to be stopped by destroying its heart.. The Heart of Destruction is the World Devourer.
Throughout Tibia, evil entities are frequently mentioned, though the name of Variphor itself rarely appears outside of Yalahar's lore, so it's not possible to be certain if Variphor is behind all the evil. Another direct account of Variphor is discovered when the players deal with the Cults of Tibia, with Gerimor noting that "the fiend from beyond" discovered by the Yalahari, which was involved in Ferumbras' ascension and its impact on the fabrics of reality, could also be the influencing force behind the creation of these cults. At the end of the questline, we learn that Zarcorix, an Yalahari, was behind The Source of Corruption.
Later, an NPC with a vast knowledge of Variphor, Dedoras, further explains that it was its minions that stole the god-killing Weapon Ferumbras was also trying to obtain, and they now seek to steal the ancient knowledge of Zathroth, hidden inside his Secret Library, which is required to use the weapon. When trying to prevent this from happening, the Tibians fail to protect the secret knowledge while fighting The Scourge of Oblivion ("AMIDST THE DISTRACTION THE KNOWLEDGE ABOUT THE GODBREAKER HAS BEEN STOLEN!"). Variphor minions now possess both The Godbreaker parts and the knowledge to use it.
There are also other factions and creatures that were victim of an unknown evil, possibly Variphor:
- Zao, the Lizard land, was attacked by a "Corruption" that devastated the lands and created new races of creatures. It's possible that this corruption was caused by Variphor and lead to the Wrath of the Emperor.
- The lore of the Warzones revolve around Those Below, fearsome army generals that are organizing attacks on Dwarves and Gnome settlements and outposts. In some books, it's questioned whether they are the bosses or working for a stronger entity, which could be Variphor.
- The Were-sickness, which begun in Grimvale and started spreading across Edron, has an unknown source. After the discovery that the Ley Lines were being used to fight the protective magic cast by the Edron Academy, suspicious arouse that there's more to the sickness than it being a simple contagious disease. The hideout of the Werecreatures bosses resembles the Warzones 4-6 significantly, since both areas have Lava Flows and Obsidian Pipes.
- The Order of the Falcon used to be an order of the best Knights of Tibia, until they started becoming evil and ended up as undead knights. Also, the Falcons hold one of the secrets to access the Secret Library.
- The Dreamelves were also peaceful creatures, but something corrupted them and they started fighting each other, probably as an attempt to release The Nightmare Beast which they locked up many years ago.