One thing you should always keep in mind while building your character is your ultimate goal.
Alright. Let me present the Viserys I want to roleplay in this quest. Maybe he'll start out that way. Maybe he'll become this person through character development.
Viserys wants two things: Firstly,
freedom through arcane power. Secondly,
entertainment.
Firstly, he is always searching for more arcane power. Not out of lust for the power itself, no - by now he could not care less about commanding others. Years of being the "beggar king" have taught him the pointlessness of status and prestige. He just doesn't care any longer for crowns and thrones. At some point in the recent past he finally accepted that House Targaryen had fallen through its own folly, and with that came the realization that the throne he had been trying to regain really meant nothing to him. He abandoned the mad quest for his ancestor's lost kingdom, and in doing so Viserys found that what he truly desired was freedom - and the power to ensure he would always remain free, no matter what the world may throw at him. And with that discovery came magic.
Let others play the Game of Thrones - Viserys knows where true power lies.
True power lies in conjuring food and shelter from thin air, never having to go hungry again, never having to see his family go hungry again.
True power lies in becoming someone else with but a word, and letting the clueless world think the last Targaryen missing, while Viserys lives his life however he damn well pleases.
True power lies in being able to laugh into the cheesemonger's face when he tries to flatter and manipulate you with transparent lies, for there is nothing he can offer you that you need.
And last, but certainly not least, true power lies in being able to do a casual "Scry & Fry" on that fat stag on the pointy throne, should the idiot ever get the idea to send assassins after you.
In short: True power, and with it, freedom, lies in magic. That's why Viserys is always searching for more of it.
Secondly, Viserys remembers. He remembers being the beggar king. He remembers living in constant fear. He remembers abject poverty and ridicule in spite of being royalty, and supposedly owed respect and comfort. He remembers
every last indignity the world has inflicted upon him throughout his short life. And he has come to understand that this is simply the nature of the world he lifes in. He understands that life is a tragedy, and man is meant to suffer.
Screw that.
No more. Viserys means to have his revenge on this cruel, worthless world. Not by dedicating himself to some grand act of vengeance upon his mortal enemies, oh no - that would only mean adding to all the pointless drama, playing right into the hands of uncaring fate. Instead, by utterly and completely disregarding the way things are supposed to be. Honor? Glory? Being the grandest, greatest king in the Game of Thrones? Bah! Rubbish, all of it!
Viserys is not a player. He wants to be the guy who walks by and flips the board for his own amusement, then laughs at the players crawling all over the floor to collect their pieces and save their precarious position. Robert, Tywin, Braavos, Volantis, Starks, Tullys, septon or slaver. Doesn't matter. Viserys wants to mess with all those assholes equally. He comes, he goes, and nothing is the way it used to be.
In short, I want Viserys to attain ultimate arcane power. And use it to
troll everyone.
(Yes, I am aware that this is essentially Viserys-in-name-only. That's intended, canon-Viserys is a fool, and also boring.)