Lost Sword gear system is like any other RPG; from white for trash gear all the way to yellow for legendary.
We don’t recommend upgrading every single piece of gear unless you’re a new player and have nothing else to equip.
If you get at least 2 good lines, you can upgrade that piece to use until something better drops. Min maxing gear in this game takes ages so be patient.
You can completely ignore flat stats. They don’t scale well considering the numbers you can see in this game so % will always be better.
Also please remember this is only for special stats and there are plenty of good pieces with main stats that will look “weak” if you only look at the substats.
Everything in this game benefits from ATK %. Your damage AND even your heals, so every character benefits the most from this stat.
After ATK the only thing that matters is that the other stats are also % instead of flat. Also remember not all pieces of gear can get ATK as a substat (armors).