"All right, enough talking. The Lahmu are coming. We need to get out of here, now."
Just as Flat Escardos and Svin Glascheit were about to speak, Luvia looked across the enormous pit at the Lahmu pouring into it and suggested they leave. They still had several Servants with them, but being surrounded by Lahmu would be dangerous all the same.
Fortunately, almost none of the Lahmu left aboveground could fly, or they would have been in even greater danger. Flying Lahmu were particularly dangerous, so Shen Fei had prioritized eliminating them.
The Servants who remained above were those ill-suited to fighting Tiamat, including Ushiwakamaru, Benkei, Black Jeanne, Medea, Bedivere, and Da Vinci.
They had not been left behind because they were weak, but because their Noble Phantasms were mostly meant for close combat. Fighting Tiamat at close range was impossible, since they had no way to approach her. Ushiwakamaru's Noble Phantasm, for instance, could cut down the Beast Goddess without a problem, but she could not even get close enough to strike Tiamat.
Of course, someone with a divine Spirit Origin like the Leopard Men would fare a little better.
"Ahhh! What took you so long? Hurry up and do something!"
In the underworld, Ereshkigal shouted at Shen Fei and the others as soon as she saw them descend from above. She was using her Noble Phantasm, Kur Kigal Irkalla, to hold back the Chaos Tide that had fallen into the underworld along with Tiamat.
Tiamat's Chaos Tide was a forbidden substance that could not be touched, even in the underworld. Despite her love of researching the unknown, Da Vinci had chosen not to study it. It was simply too dangerous.
"I'll handle it." At Ereshkigal's plea for help, Shen Fei immediately prepared to help her hold back the