The weight of one's words changes incessantly with one's strength.
Initially, Giharin saw Gaven as an ambitious young man. His promises were merely stepping stones for collaborating with the Tesser Yama Kingdom exiles, valuing their Firewine Race's extraordinary forging skills.
At that time, Giharin might have seen a glimmer of hope in him, but it wasn't much, merely cooperating with the thought of not losing out.
Many matters are founded on normal commercial cooperation.
However, with the reboot of Colossus City, the other party still kept their original intentions and greatly delegated power, which was truly commendable.