Apart from other valuable rewards, the triumphal challenge battle pass yields a special resource: trophy coins.

These coins allow you to purchase various unique rewards in the Triumphal challenge shop, such as dragon orbs, legendary captain shards, elite summoning scrolls, and other resources.

The most valuable reward you can obtain is a unique permanent city appearance. It is the most expensive item you can buy in the shop. However, each city skin you purchase yields a permanent 5% bonus to your army's strength. Note that bonuses to army strength granted by each unique city appearance stack, i.e., they apply even if you change your city appearance.