Troll Lord Games

My group got in a fight with a minor vampire, and before they were able to repel it the creature had taken the party cleric from 2nd down to 0th level.

At 0 level I told him that he lost all his class abilities (spells, BtH) and his hit points are at 1/2 of what they were at 1st level. But I'm not sure what to tell him about XP. They earned 285 XP for that session, so I don't know if that puts him back at level 1 (what XP limit do people use to distinguish 0-level from 1st-level characters?). If so, then I guess he only needs one restoration spell to get him back to where he was at 2nd level.

What do you guys think

I think you were more than kind to allow the character to remain alive at 0 level, where the default assumption is that is death and renewal as a vampire spawn. Therefore, I'd keep him as 0 level and require him to earn half of what 2nd level requires to get back to 1st, or a double restoration effect.