The Grand Summoning Array was a summoning formation for calling forth Grand-rank Heroic Spirits, and it took far longer to activate than an ordinary summoning ritual. Their plan for facing Zeus this time was simple: stall for time, safely activate the Grand Summoning Array, summon a Grand-rank Heroic Spirit, and then make that Heroic Spirit the centerpiece of their battle against Zeus.
After seeing Zeus, Macarios had apparently been intimidated and had not activated the Grand Summoner right away. That was why Shen Fei had quietly reminded him. This conversation was the perfect time to activate it. Even if Zeus noticed their little move, he might not necessarily intervene to stop them.
That conclusion was based on Zeus's personality. Gods were undoubtedly arrogant when facing humans, and Zeus was the king of gods, an omnipotent deity. Even if such a being knew humanity was using some means to defeat him, he likely would not simply destroy it outright. He would probably want to see what that means was first.
"Lady Europa, it's dangerous here. Leave this to us." When Zeus was about to pass judgment on Europa, Mash immediately stepped forward to her side and told her to retreat. At the same time, Musashi and Caenis advanced several steps and stood alongside Mash, facing the omnipotent Zeus head-on. Europa understood that she could do nothing against Zeus, so she immediately followed Mash's advice and retreated to the Macarios siblings.
"Goddess Athena, God of War Ares, Sea God Poseidon. Though they are not vessels of possession, I can see the power of your brethren enveloping you. I see. They are the brethren I personally slew. What a fated lineup."
Zeus's gaze shifted to Mash and the other two. As he looked at them, he seemed somewhat contemplative, as though recalling something.