Because Gilgamesh had already bitten the dust. He had gone and gotten himself killed by recklessness yet again.
Same old story: the king sought pleasure, the king got his elbows broken, and the king recklessly rampaged across the entire moon.
So, was it time for him to seize the Holy Grail? After briskly tossing the magic circle blueprints and drawing materials to Waver, Li*Han patted his backside and took off, leaving Waver staring dumbfounded at the pile of materials and designs.
"Couldn't you have fought properly?" Li*Han sighed helplessly as he looked at the mutilated man before him. "Acting on your own like this will cause me a lot of trouble."
To fulfill his promise, Alcaeus had abandoned the safest strategy and chosen to confront Gilgamesh head-on. Though he had gained immensely, the damage he suffered was even more horrifying. All the lives granted by Twelve Trials had been exhausted, and the Divine Beast's Pelt had been destroyed. If not for Chiron's immortality sustaining him, Alcaeus would not even have been able to stand here.
But this was already his limit. Alcaeus had used that Noble Phantasm to block Gilgamesh's fatal strike, but activating it meant adding Chiron's suffering to his own. If he kept the Noble Phantasm active for too long, the pain would continuously accumulate until it destroyed the user's sanity.
"But that is merely trouble, isn't it?" Alcaeus spoke calmly, as though he were discussing some trivial matter. "Even if Gilgamesh and I both leave the stage, you have a foolproof way to defeat Saber and her Master and obtain the Holy Grail, don't you?"
"You're being awfully unethical." Li*Han sighed. "Our pact was that I would help you defeat Gilgamesh, and you would help me seize the Holy Grail. Now you're suddenly quitting, after mooching off