Runner is a stat boost that affects the speed and stamina of the character, but lowers the quality of items gotten.
Tier 1
+2 Speed, -5 Item drop luck.
Tier 2
+5 Speed, +2 Stamina, and double EXP from race submissions. -10 Item drop luck.
Tier 3
+8 Speed, +5 Stamina, and double EXP and +5 Luck from race submissions. -15 Item drop luck.