Not a PC that's going to be doing it... actually it's a "Grey Area" NPC - who's going Very Dark after the ritual. The point is that they will have four weeks in which to find and defeat him before the whole ritual finishes or becomes solid. At which point he's a total plot device, but before which he could (in theory) be defeated. I'm going to start increasing his stats, adding stunts, and refresh every week. So if they can find him quickly it will be easier to defeat him, but if they wait around for 'help' - well it's going to be tougher.
The ritual finishes and instant increase:
Like +1 to his stats, +1 Stunt, +2 refresh (in addition to toughness)
End of week 1 through week 2
Another +1 to stats, +1 Stunt, +4 refresh (in addition to speed and recovery)
End of week 2 through week 3
Another +1 to stats, +1 Stunt, +6 refresh (the toughness and recovery each go up a category)
End of week 3 through week 4
Another +1 to stats, +1 Stunt, +8 refresh (recovery goes to Mythic with a catch)
End of week 4 = total plot device....
thoughts on the progression? Any alternate advancement would be appreciated.