[Endless Growth was an auxiliary-type of spirit artifact. It wasn't used for combat, nor does it have any flashy effects when used against anyone.]
[It only has one purpose due to it manifesting that spirit avatar ability when the master of this spirit avatar died. It was none other than the ability to use this spirit artifact on an existing weapon, and letting that weapon possess the trait of Endless Growth.]
[The Endless Growth trait allows a weapon to have two growth paths, and either could be chosen at any time, whichever was more convenient.]
[The first one was that the weapon with the Endless Growth trait can be bound to a user, and it was only once. Afterwards, the weapon will grow alongside the user, its grade always being the same as the user's power rank.]
[The second path was consuming weapon upgrade materials to increase the weapon's grade. This one could be used in conjunction with the first path.]
