20 апр. 2020, 17:5820.04.20
It means how many times that substat was upgraded.
Depending on rarity your upgrades behaves differently
legendary will have four upgrades to substats (at lvl 4,8,12,16)
Epic will have 3 at (lvl 4,8,12 at 16 it gets a new substat instead of upgrading existing one)
Magic will have 2 (lvl 4, 8 at 12 and 16 it will get new substats)