The Silver City was massive, and the castle of the Imperial Princes was far from the entrance. So, if they were to simply walk, it would take days for the group to arrive. While the group could move at Hypersonic Speed and reach the castle in less than a minute, it would still generate all sorts of inconveniences for the people, not to mention it would leave them in a bad name for their lack of manners. Although there were vehicles that could help them move, they were still too slow.
Luckily, they had a much more efficient way of transport. Damian guided the group toward a small location full of formations engraved in the ground, and it didn't take long for them to recognize them as teleportation matrixes. There were guards around it since not anyone could use it.
Even Cain, with his title as a Colonel, would need help getting access to them since there was a need for authorization from the Imperial Court, but Damian already had that covered.