Quick Riposte 2 or Swordbreaker 3 on +Spd -HP Eldigan?

IMO, QR.

I would definitely go with swordbreaker 3 you will win more matchups

I'd run Swordbreaker 3. You already one shot every common green mage and can probably kill most axe units as well (or take minimal damage from them at the very least). With swordbreaker, you'd beat just about every sword unit you are matched against.

my eldigan is - spd + hp, the opposite of yours... i put sword breaker, cause he could be in the meta against others sword users for 2-3 battles.

SB is niche against red meta, but QR garantees specials after battles against every melee meta.