The oblique (objective) form you functioned previously in the roles of both accusative and dative, as well as all instances after a preposition.
Chris Martin is lead singer, rhythm guitarist and pianist for the alternative band Coldplay. The group has won multiple Grammy Awards over the years, one being for their debut album.
Champion is not the first popular musician to be cast in Game of Thrones. The announcement of his involvement follows the revelation that Gary Lightbody, the lead singer of band Snow Patrol, will also appear in a minor role during the next season. Lightbody tweeted a photo of himself in Thrones-appropriate costuming earlier in the year.