Marcus is one of the sparklepire triumvirate who rules the vampire world, along with Aro and Caius. He has been with the Volturi since, as his name suggests, the Roman Empire. This is despite an attempt by his twu luv, Aro's sister Didyme, to break off and do their own thing as opposed to helping Aro take over the world. Immediately after telling Aro about this, Didyme just up and died the crap out of herself(no really, it was an accident). Marcus has noticed nothing suspicious about this, because he is not very smart.
Physical Appearance Edit
Since Bella states that two of the Volturi are dark-haired, and Caius is confirmed as the blond, Marcus must have dark hair. Like the other extremely old vampires, he has oniony-looking skin. His eyes are red due to his non-vegetarianism. He could also look like a zombie, as Smeyer says he is zombie-like because he lost his Twu Wuv.
Marcus is an emo zombie because he lost his wife Didyme. He's even worse than Edtard. Instead of getting over it and moving on, he becomes, as quoted by Smeyer, an ' apathetic zombie'. Why Aro keeps him as one of the leaders of the Volturi is a question that will never be answered. He has all the personality of a teatowel with a face drawn on and never speaks, which are not the traits that make a good leader. However, many people argue that he still has more personality than Bella.
All That Wasted Potential Edit
Consider the consequences if Marcus had realised during the books that Aro had murdered Didyme. Vampiric war to the death, anyone?
Marcus's love story with Didyme was also more interesting than Bella and Edward's arguments over who's prettier.
Marcus is also known as St. Marcus in Volterra, famed for ridding the city of vampires, and there is an annual festival in the city (despite the fact that the actual patron saint of Volterra is St. Justus). Obviously the Volturi are still in residence, but if Marcus once single-handedly kicked out or killed every vampire in Volterra who wouldn't serve Aro... To be honest, there is more action in that backstory than in all of the actual books added together, and even if it was staged, then faking a vampire throwing all the other vampires out of Volterra (imagine Aro directing the rehearsals) is much, much more interesting than a dull "love" story.
Special Meyerpire Power Edit
Ok, this'll give you some laughs: Marcus can see... Relationships! ♥ ♥ ♥ Yep. That's his
super-cool ridiculous power. Hey, can he see how much I love candy corn?
This is Smeyer's explanation of how Marcus's ability works:
"Marcus’s gift is actually quite valuable in the hands of someone who knows how to use it. For example, imagine Marcus on the battle field. He sees the binding ties between the enemy the guard faces. He can tell who the leader is just by watching the way the others are tied to him or her. He can see how to destroy the resistance simply by picking off a few key people. He doesn’t just see romantic relationships, but also ties of family and friends, loyalty and devotion. He can tell if any given person would die for another. Off the field of battle (as the Volturi rarely leave their home), Marcus’s gift is valuable politically (for lack of a better word). It’s an amazing gift in a diplomatic situation. Plus, when you’re sitting on an empire, it’s nice to be able to see when someone’s loyalty starts wavering. Or if anyone is getting too fond of anyone else. Can you see the potential now? Marcus didn’t get where he is with some fluff skill."
Antis believe the only reason his power was created was to rub in how much Bella and Edward "Love" each other. This is a useless power on the battlefield. Didyme's power to make people happy was actually far more useful to Aro, in terms of negotiation (people are easier to negotiate with when they're high) and recruiting for the Volturi Guard. And as Smeyer implies that Chelsea has been keeping Marcus in line since Didyme's death, Aro still had one person who could see relationships even with Marcus gone.
"Wait! I'm getting something! Brad Pitt... Still... Has feelings... For Jennifer Aniston!" Yep, that'll totally help on the battle field. Right?