We would still consider Raiden to fall under the category of an issue that you could have "healed" upon entry, at which point he could get his sustenance from emotions or another source.

But since that doesn't seem to be what you're going for, we're fine with him finding alternatives in Verens! The hospitals could recruit some researchers or other Otherworlders to whip something up over the course of a month or so that could purify his blood using a combination of positive emotions and crystal/core power. If that wouldn't be fast enough, he could also find dunamis healers in Verens or Shaarnath to tide him over until it was completed. A nutrient paste would be easy enough to create with their current level of tech, as long as he specified what he needed.

And for further CR opportunities: the hospital won't necessarily ask him to pay for it, but if he wanted to do some errands for them... ;)