Did this custom last year,inspired by Jin's AoA Magneto.Base is a Batman,everithing else is sculpted with plumbers epoxy,head is fully sculpted (I wanted to keep batmans head as fodder,these figures are quite expensive around here...).The metal spike thing is made out of wire and hot glue.

As for some backstory.I'm designing most of my customs on this universe.Wrigth now I'm working on a Hulk,an Iron man and an Captain America.I'm pretty lazy,so these my take a while.

The almost bankrupt of the kree empire in their war with the skrull and the growing expansionism of the Shiar empire disturbed the delicate balance of power in the universe.The destruction caused by the anihillation wave served as a final push to a completely chaotic and agressive universe.After years of intense conflicts,wich depleated most of their resources,the kree alliance(that had long dominated the skrulls) and the shiar empire came to an understandment.Both empires started reconstructing themselves,gathering resouces and expandig in wars with other small empires.
About 15 years after the first skrull invasion,wich lead the remnants of the skrull empire to its final derrocade,a massive alien fleet entered the sol system,intending the simple obliteration of the human race (and its variants)and taking on earth, for its strategicaly valuable position between Kree space and the anihillation wave space,formerly Skrull's.The fleet should set up an advanced post for resuplying before proceeding to the Anihillation Wave space.
The fleet,composed of kree-skrull ships and most of the Great Armada of Shiar,was completely anihilated by an automated defense system positioned on the Kuiper asteroid belt.
The Sol defense system was constructed for the single purpouse of destroying this fleet,by an newly founded UN force,called Spear (just Spear, no acronyms).This force was assembled after an unprobable candidate came to the world speaking about future events. The mutant known to the world as Apocalypse took over communications all around the globe,and claimed to have spoken with Celestials, who about him about the end of his beloved mutant species, along with the rest of mankind. Shield sent for recon missions on shiar space,and came to the conclusion that Apocalypse's warning was a very probable outcome, and so the world started preparing itself for the war to come.
And the war came.
After the destruction of the first fleet,the Kree-Shiar alliance was quick to respond. The Earth's forces, although greately outnumbered, possesed a far more advanced tecnology, provided by years of study on numerous alien technology ,and unmatch intelects as Reed Richards and Tony Stark.Earth also possed extremely powerfull beings on their side as the Silver Surfer,who decided for protecting that planet,and the Hulk,who later on the war took over alone the Shiar Dockyard Worlds ,which dismantled the shiar fleet capabilities.
During the war, Magneto served as an last defense weapon based on Earth. Four months after the first strike, when the Sol defense system had already been breached, a Kree fleet approached Earth. With Earth’s nuclear arsenal depleated by months of constant attacks, an experimental device was used to magnify Magnetos power. Most of the fleet was transformed in what became the Iron Moon. An Skrull troop carrier managed to enter Earth’s atmosphere, crashing in the Acre State,Brazil. The 17 surviving specimens were captured after two weeks of fighting, by an taskforce commanded by Magneto and his X-Men.