In Abbysial Ruins, you find items that you can find no where else in any game. (Except the plates). You cand find a series of rare Relic Items to sell to the Maniac who lives in the Villa west of town. You can also find Arceus plates there, which change its types according to the plate. The Relic Items can be sold for unspeakable prices and are a great way to make fast money in the game. If you were to get every single Relic Item, the price would total to 1,706,000 PokeDollars.