Domina

Its a gladiator simulator sandbox game. It is possible to control individual gladiators but I find it more fun to let the cpu do it for me and watch the fights instead. You can choose a fighting style, equipment and stats to train and it's a lot of fun.

Train gladiators -> fight gladiators -> repeat!

Forza Horizon

The first game is my favourite so went back and played a bit. Currently on the orange wristband.