Kristoffer left Arsenal at the end of 2014 to join FC Midtjylland, ending his three-year stint with the Gunners.
Technically-gifted midfielder Kris featured regularly for the under-21s and soon made his debut for the first team, scoring a penalty in the shoot-out win over West Brom in September 2013.
Composed in possession and accomplished in front of goal, the Sweden Under-21 international was a mainstay in the 2013/14 Youth League side, helping them reach the quarter-finals of the competition.
He scored his first goal for the senior side in a pre-season friendly against Boreham Wood in July and travelled with the first team on their trip to New York.
Kris began the 2014/15 season by securing a loan move to Danish club FC Midtjylland before joining permanently in December.