Sunlight will kill him if he gets it in doses that are too large. Fire can do that too, or very, very grave injuries - being staked by itself won't. If he doesn't get enough blood, he will frenzy, and if he can't get blood through that, he will fall into torpor, a kind of supernatural slumber, which in his case would last a few weeks. Without is dogs, he will be more vulnerable to losing control to his beast within. He can only ingest blood and nothing else; blood that carries a toxin or some very specific illnesses (like the black death) will harm him. His biggest weakness probably is that exactly, the danger of losing control to his beast - frenzy and rötschreck. The first is the aggressive mode, which will make him attack whatever caused the reaction, the second will make him flee, though he will fight to get obstacles out of the way. Since he's a Gangrel, frenzies will also give him additional animal attributes. I'd count both of these as weaknesses mostly because he's out of control during them, though.
Weaknesses
If he doesn't get enough blood, he will frenzy, and if he can't get blood through that, he will fall into torpor, a kind of supernatural slumber, which in his case would last a few weeks.
Without is dogs, he will be more vulnerable to losing control to his beast within.
He can only ingest blood and nothing else; blood that carries a toxin or some very specific illnesses (like the black death) will harm him.
His biggest weakness probably is that exactly, the danger of losing control to his beast - frenzy and rötschreck. The first is the aggressive mode, which will make him attack whatever caused the reaction, the second will make him flee, though he will fight to get obstacles out of the way. Since he's a Gangrel, frenzies will also give him additional animal attributes. I'd count both of these as weaknesses mostly because he's out of control during them, though.