Although the death of Oy was foreshadowed, when it finally occurred I found myself upset and angry.
It seemed avoidable. Oy saves Roland by attacking Mordred, yet Roland, once alerted, fails to save him. We have seen countless examples of Roland’s almost superhuman speed with a gun, and yet at this point he seems to take forever to react. He even finds time to shout at Mordred before he even reaches for a weapon. "Put him down, Mordred!" Yeah, right - that's going to work, isn't it. Only when poor little Oy has suffered a fatal injury does he finally pull the gun and shoot.
This upset me more than anything else in the whole story, as it seems so needless, as well as uncharacteristic.