Ok, sorry if this is written on its own page. Meta Kirby has one storyline dedicated to himself, with three others that revolve around him. (Four Decently Drawn Comics are done on these, and part one of the storyline is nearly complete)
Ok, so let me cut it down to the short version...
Meta Knight attempted to take over Popstar again with the Halberd. Kirby damaged the Halberd, which sent it careening into a portal to an Alternate Dimesnion. The Halberd crashed on the Star Of Pops, and Meta Knight was knocked out cold. Kirby awoke first and proceeded to explore the planet, where he met a bunch of Batamon. The Batamon repaired the ship and by the time Meta Knight awoke, the Halberd was as good as new. So, Kirby and Meta Knight left the Star Of Pops, but as they were leaving, the planet exploded, and the resulting shockwave (along with the portal) shoved the Halberd straight back to Popstar!
Anyhow, Meta Knight finds Batamon on his ship, one Green Batamon and two Blue Batamon. Meta Knight trains them, so they can help defend Popstar if the planet comes into danger. The Green Batamon beats the two Blue Batamon, and thus he is promoted to "KnightHood". The two Blue Batamon dissapear and are not seen for a long time. The Green Batamon is given the name, Olive. Olive is sent to defeat King Dedede in combat, but Olive is instead defeated by Dedede, who whacked him out of his castle with his hammer. Olive lands in front of a sleeping Kirby, Olive defeats Kirby (who was very groggy) and he is overjoyed. When he told Meta Knight, Olive neglected to tell him that Kirby had just awoken from a deep slumber.
Needless to say, Olive goes insane with power because he beat Kirby while Meta Knight never could (just look at Squeak Squad when he tried his hardest to beat Kirby) so Olive flies away from the Halberd. He goes on this journey to absorb Dark Matter so he can become ultra powerful, and he comes back to Popstar, fully corrupted. He intends to destroy Meta Knight first, then the planet itself.
Luckily, Meta Knight manages to beat Olive with the help of Kirby and King Dedede.
However, in Mirror World, a counterpart of Olive is created. He is darker and more malevolente than Olive. His name is Meta Kirby. Because Olive absorbed Dark Matter and Meta Kirby was born during that event, Meta Kirby has a certain skill that allowed him to inhale Dark Matter although he can still retain self control. So yea, thats why Meta Kirby looks all corrupted like that in my acoount image. Just because he can control himself dosent meant he dosent suffer the effects of a numerous amount of Dark Matter within his system.
Ok, i know that this is not even close to canon. I just took the outline of Kirby canon and twisted it a bit. I didnt even come up with the Batamon until playing Kirby's Dream Land 3. Before that, they were described as being like Kirby's race. And much MUCH later i explained why the Star Of Pops exploded without warning. So yes, it is a very long storyline, with new plots and explanations in each section. I dont know whether or not to share it on here. (Again, very sorry if this shows up as its own page)