The team that's been rumored to have the most interest in Karlsson is the Edmonton Oilers. In fact, numerous Oilers fans have requested GM Ken Holland to find a defenceman that can move the puck, and Karlsson definitely fits the bill.
Adding Erik Karlsson would definitely make the Oilers a significant threat in the Western Conference. Though this would imply giving up a great developing defenseman in Evan Bouchard, Xavier Bourgault is only in his first professional year, a 1st Round selection in the deepest draft since 2015, and a high-producing defenseman in Tyson Barrie.