There's this really good Hunt Quest from Ivanos Tower's quest board, just have to kill 5 of these EZ AF mobs for 500,000 XP, 160,000 Gold and 27,000 RC and 1,250 AP.
Best spot I've found for these is right outside Ancient Underground Shrine, closest portcrystal is Glywndr, there's 3 of these dudes right here but only at nighttime.
It expires in 9 hours by the way.