A weapon’s quality determines how many times it can be improved within its rarity.
The rarity is represented by stars, which can be filled by improving the weapon:
⭐: Rusty.
⭐⭐: Decent
⭐⭐⭐: Fine
⭐⭐⭐⭐: Excellent
⭐⭐⭐⭐⭐: Masterpiece
To improve a weapon, it needs to be refined using weapon scraps.
After it’s refined, it can be improved using glue, weapon components, and a weapon essence of the right rarity.