#okami-117

So essentially, Blacklight is 100% fatal to Kindred because it's trying to aggressively rewrite them, which then begins to cause a spread of necrosis - the body is being changed from something within them, rather than without, and essentially begins to enter a rapid onset of decomposition. That's why Valerie went into Frenzy after being infected - she was already damaged from fighting, and suddenly she was rotting and it caused the Beast to panic.

Blacklight is that way because it was engineered to emphasise Redlight's ability to rewrite and speed up that process exponentially. It's a weapon that was designed to be aggressive and efficient, and its very good at killing Kindred.

However, while Blacklight is the perfectly refined weapon that Blackwatch wanted, Redlight was a naturally occuring virus that had been altered and experimented with. Blackwatch was still trying to figure out what it could do, so it's significantly less aggressive in comparison. It proved dangerous as hell when it fell under Elizabeth Greene's control, but compared to Blacklight? It's like a sneeze versus an atomic bomb.

So with Redlight, there's a significantly lower chance of rapid onset decomposition as the virus takes time to adapt to their physiology rather than trying to violently overwrite it. Provided the Kindred doesn't continue to feed on contaminated sources, the infection can even burn itself out of their system. During this period of infection, the infected Kindred might even get some benefit from it; they may see an improvement in cognitive or physical skills, and their disciplines might become more potent. These changes are permenant, even after the infection burns out, so it tends to be a leg up for those who manage to catch it. Kindred of higher generation tend to see more benefits than those of a lower generation.

But there are some pretty big risks that make it a dangerous venture:

Infection can last a month, and during this time, the Kindred is infectious. Anyone they feed on, be it mortal, animal, or even other Kindred, will catch the virus from them. Kindred might consider this an acceptable risk among each other because Benefits, but for mortals? It's almost certain to be fatal. Ventrue are the most likely to cause an outbreak because of their inability to feed from blood bags, which forces them to feed on their usual prey and spread the disease.

The risk of rapid onset decomposition isn't non-existent in Redlight and can still occur, which almost always results in Final Death if it isn't treated. The cause tends to come down to the variant strains of Redlight - some are more aggressive than others, and are more likely to trigger the reaction. Tremere are the most susceptible, though no one's been able to figure out why.

The benefits granted by Redlight can be addictive, and so some Kindred might go out of their way to become infected so that they can grow stronger. This can lead them to becoming a Plaguebearer if they maintain the infection within them long enough for it to become a part of them.