He doesn't like this.
Sylar knows he needs help if he's going to take on Parkman and Petrelli -- he might be smarter than both of them, but they're better armed, and he's never been good at fighting on two fronts -- but people don't just offer people like him help without a catch. Arthur's going to want something from him in return, and as good as he usually is about repaying kindness where kindness is offered, he likes to do it on his own terms. He wants to be the one who decides what and when people get something out of him, not have a debt held over his head, and he knows that's how it's going to go with Arthur. The Petrelli patriarch's already tried it, feeding him some bullshit story about how he's his son to him over the phone to try and make him feel obligated, and he doesn't owe him a damn thing yet. It can only get worse from here on out, he figures, and it's not like he can't find Suresh on his own. He's done it before, biding his time until the heroes let their guard down and move on to more important things, and he's got all the time in the world to wait now. They don't.
Unfortunately, however, neither does Suresh and as angry as he is, he's not too keen on waiting to reclaim what's his and what should belong to him, and that probably explains why, against his better judgement, he gets out of the car and stalks up to the building. If this goes badly, he'll just kill Arthur and go his own way. He makes a show of making sure Arthur knows that's in the cards, too, blowing the door off the hinges as he reaches it in a disturbing display of power. Arthur told him not to kill anyone on his way up here, and he didn't, but he never said he couldn't wreck his little house of cards when he got here.
Sylar knows he needs help if he's going to take on Parkman and Petrelli -- he might be smarter than both of them, but they're better armed, and he's never been good at fighting on two fronts -- but people don't just offer people like him help without a catch. Arthur's going to want something from him in return, and as good as he usually is about repaying kindness where kindness is offered, he likes to do it on his own terms. He wants to be the one who decides what and when people get something out of him, not have a debt held over his head, and he knows that's how it's going to go with Arthur. The Petrelli patriarch's already tried it, feeding him some bullshit story about how he's his son to him over the phone to try and make him feel obligated, and he doesn't owe him a damn thing yet. It can only get worse from here on out, he figures, and it's not like he can't find Suresh on his own. He's done it before, biding his time until the heroes let their guard down and move on to more important things, and he's got all the time in the world to wait now. They don't.
Unfortunately, however, neither does Suresh and as angry as he is, he's not too keen on waiting to reclaim what's his and what should belong to him, and that probably explains why, against his better judgement, he gets out of the car and stalks up to the building. If this goes badly, he'll just kill Arthur and go his own way. He makes a show of making sure Arthur knows that's in the cards, too, blowing the door off the hinges as he reaches it in a disturbing display of power. Arthur told him not to kill anyone on his way up here, and he didn't, but he never said he couldn't wreck his little house of cards when he got here.