The best Dark Miscrit of them all, Dark Equestrion, is available this week in Volcano Island! Dark Drowsie made the switch over to Sunfall after its stint in the Volcano Island BA last week.
As for Battle Arena prizes, Flutterpat has made a triumphant return to Sunfall Kingdom, and Dark Felis is in the VI Arena. There's also another, more appropriate gold prize in the VI Arena this week.
Also- get the Frozen Coin relic and Cyberdillo while you still can! They'll both be leaving the shop after tomorrow.