I believe Xander is going to try and help out during the earthquake as much as he can by transporting injured people out of destroyed buildings via the shadows. He'll try to be discreet with placing them outside and never really giving away his identity by fully emerging from the shadows. (...Then again, he might be scaring a LOT of people by materializing a hand or arm to grab a hold of someone to bring them in to the shadows. Whoops.)

I don't think he'll be able to help out much with other things since he considers himself to be emotionally compromised due to an echo involving his father (even though he made no indication of such on his recent post) and struggling with the idea of leaving the city when the holidays come around. But! I'm not opposed to having other people drag him out or try to convince him that they could use his help, unless it is for moral support which might not go over well.