Mesonak- Is the lord of all destruction and the brother of Solek,Photok and Tanma. He was previously a being made almost exclusively from lime green. After being defeated by Solek for nearly destroying the gigaverse, Mesonak's skull floated around in space untill it hit planet Earth, where Mesonak's reincarnated form is living now.
In the beginning Mesonak was an unbelivably big cloud of corrupt lime green, which then evovled into a giant uncontrollable beast of lime green, that in the end evovled into Mesonak. In his final form Mesonak accepted some grey colors, but turned it to black instead. Mesonak was the only one of the four brothers to not evovle into a Av-Matoran God, since he didn't accept the grey colors in the end.
Mesonak's high acceptance of corrupted lime green limited Mesonak's creative or artistic creation skills, it was only through his black colors, that Mesonak could use his creation powers. However, if Mesonak created something combined with the lime and black colors, then it could only create destructive things (i.e weapons).
Solek discovered his lack of creation skills, so he gave him a job of destroying failed creations made by the Av-Matoran Gods. One of the first things Mesonak was ordered to remove were the shadow matorans known as Vultraz, Raidak, Kirop and Gavla. The shadow matoran were origninally Av-Matoran deities, who were corrupted by a special source of lime green. The shadow matoran planned on overthrowing the Av-Matoran Gods, and then rebuild the gigaverse to their suiting. They decided to create the Mask of Evil Lime Green, so they could produce enough corrupt lime green to destroy the gigaverse. At first the Av-Matoran Gods tried to convince them not to do it, but since they resisted them, Solek unleashed Mesonak to stop them. In the battle Mesonak was given a powerful weapon by Solek, which was a prototype of the Solekimu hammer. The hammer was so powerful, it could even kill an Av-Matoran God.
At first Mesonak was beaten pretty badly, but after becoming increasingly more angry, he mercilessly slaughtered them all, except for Vultraz. Mesonak unleashed the "void" on Vultraz, which obliterated Vultraz completely. Through the power of the void, Mesonak could gain his knowledge and powers from his victims.
It was after this intense battle, that Mesonak discovered he has an passion for destruction. He used the knowledge from Vultraz, so he could create the Mask of Evil Lime Green.
Before he created the Mask of Evil Lime Green, he made the Meso Bot, which was an enormously huge robot the size of 1000 multiverses. It was made of an extremely powerful form of Lime Green protodermis steel, that could absorb any form of attack, except orange, natural lime green/non-corrupt lime green, white and grey (the armor which the Toa Inquisistors used in Chapter 12).
With this intense great passion for destruction, Mesonak decided he wanted to battle the Av-Matoran Gods, and then end the multiverse in one giant party of chaos and destruction.
After finishing the Mask of Evil Lime Green, Mesonak tried to get to his Meso Bot, but was blocked by Solek. This resulted in a giant cosmic battle between the two, which nearly destroyed the entire gigaverse. While Solek and Mesonak were fighting each other, Photok and Tanma were creating Karzahni, so they could put Mesonak in there. In the end Solek was nearly beaten by Mesonak, and it was here Mesonak was close to putting on the Mask of Evil Lime Green. On the last second before taking on the Mask of Evil Lime Green, Solek knocked off his head with his Solekimu hammer. The blast sent both Mesonak's head and the Mask Of Evil Lime Green almost a googleplexian bio away. The attack did not send Mesonak or the Mask of Evil Lime Green to Karzahni, since Photok and Tanma were not finished with creating Karzahni yet. The knock was so powerful it knocked, the exhausted Solek into a coma. The remaining body of Mesonak was then thrown into the pits of Karzahni, where it was destroyed.
For many billions of years Mesonak's skull floated around in space, untill it finally hit planet Earth. It is unknown when Mesonak hit Earth, but it is said the team of TTV found the skull, and awakened him. Later the team would become a powerful elite that secretly ruled over earth.
On earth Mesonak ironically became more sympathetic towards all living creatures in the gigaverse. Mesonak saw the gigaverse as one giant miserable prison, that trapped all the living creatures of the gigaverse, and the only way to end the misery and suffering was to kill their "oppressors" (the Av-Matoran Gods) and end the gigaverse.