Yanggu's search began with an incomplete memory and a chosen name. Mowu travelled beside him, while Mu Yanling also shared part of the road. The remembered valley gave him somewhere to begin without telling him who he had been. He could not remember his family or even his original name.
On Ravnica, their departure comes after the battle against Bolas. Rat sees Yanling and Yanggu leave together with their three-tailed hound, who turns to stone just before the three disappear. A small observed departure confirms that these companions survived the city's catastrophe.
Victory has not made the surrounding grief disappear. Ravnicans carry away the wounded and dead while others celebrate. Yanggu's next destination is not identified in that moment; the witnessed fact is the company in which he leaves.