For a UK Court to hear it he would have to have a UK Address.
He would then have to convince the Judge that the UK court would be a Convenient Forum for it to be heard. However, as he would have had moved from Sweden to the UK to do it, then that would be hard to prove.
However, as both are part of the EU, he can use the Swedish European court.
Also one thing, he entered into the casino as a minor and agreed to the terms and conditions as a minor. As such, he would be unable to enter into a legal contract. It could be argued that as he was a minor when he accepted the terms and conditions and the casino have not asked him to agree to the terms and conditions as an adult, that he is not bound by the terms as they were when he joined.
He would then have to convince the Judge that the UK court would be a Convenient Forum for it to be heard. However, as he would have had moved from Sweden to the UK to do it, then that would be hard to prove.
However, as both are part of the EU, he can use the Swedish European court.
Also one thing, he entered into the casino as a minor and agreed to the terms and conditions as a minor. As such, he would be unable to enter into a legal contract. It could be argued that as he was a minor when he accepted the terms and conditions and the casino have not asked him to agree to the terms and conditions as an adult, that he is not bound by the terms as they were when he joined.