Ember Online

Flogging a dead horse!

How about something simple for class variation (chosen at 8th level). A +/- 1 main stats.

Example:
Defensive Knight +1 AGL, -1 STR (or END)
Offensive Knight +1 STR, -1 AGL (or END)
Tanky Knight -1 STR, +1 END

Offensive Sorceror +1 INT, -1 WIS (or AGL/END)
Defensive Sorceror +1 WIS (or AGL), -1 INT
Tank Sorceror -1 INT, +1 END

Etc.

Or traits to pick (when you first create a character).
I'm thinking Fallout (although likely other games have had something similar).
Just something to define your character a little.
A trait will have a positive and a negative.
Maybe a choice of 0, 1 or 2 traits.