The best trait is the one that amplifies what a unit already does. Use this role tier list before chasing a rare name that does not improve the unit’s real job.
Best traits by role
Unbound versus Primordial
Unbound is the headline single-unit damage roll. Primordial spreads value across damage, speed, and range, which can feel better on units that need coverage or frequent attacks. Test both on the same map and upgrade level instead of comparing the tooltip alone.
When a lower rarity trait wins
Investor is the obvious example: an economy unit needs income. Optics can rescue a unit that misses paths on wide maps, and Bolt can improve slow, stagger, or stack application. Role fit is worth more than a rare badge that does not activate.
Trait tier questions
What is the best trait for every unit?
There is no one answer. Start with the unit role, then choose damage, speed, range, crit, DoT, income, or EXP.
Is a pity trait always worth keeping?
Usually, but a farm or specialist unit may perform its job better with a lower-rarity role trait.