The advantage Zash has on the metal wheel controlled by the maniac is being able to do sharp turns. The disadvantages are it being much faster and much more willing to cause copious amounts of property damage by just swerving into a wall.
Also by throwing small localised grenades at Zash, which he can shoot out of the air but which still slow him down. And the bomber's destination is obvious.
...no. No, no, no, not now, it wasn't Nai, it wasn't meant to be Nai, please—
—but Nai is worse. Nai is worse than whatever this bomber person can do, and, and, fuck.
Zash stops giving chase, prays to whatever god nothing goes to shit because of this, and runs towards where the song is coming from.
There's a man sitting at the piano and playing a song.
"Do you remember this song? We used to play it together."
"...Nai."
"I've missed you, Zash."
"Nai, you have to stop this."
"Stop?"
"Your, your minion or whatever he is, he's killing people—"
"...I don't know who he is. A diversion. And they do not matter, Zash."
"Nai, why are you here—"
He stops playing the song and turns to face Zash. And to notice that Zash is pointing his gun at him. "You know why."
"We're doing fine, we're, we were fixing it, we could save it!"
"It? You could save it?"
"...her. We could save her."
"And then what, Zash? Another century of them using her? Using both of them? Of draining them dry while they suffer, while they—"
Both of them suddenly look up and north as if hearing something no one else can.
Knives looks back at Zash. "Is that what you call helping her, Zash? She's screaming. Or can you not hear her anymore? Are you too far gone to hear her? Too human?"
"Of course I can hear her but that's, something happened, that's different, she was fine—"
"She was not fine. She will never be fine. None of us will. Humans will keep hurting us, will keep using us, and then throw us away when they're done. Just like they always do with you."
"Nai, I can't let you. These people need the plants, they'll die without them—"
"Let me?" He stands up, and Zash's gun follows his movement. "You would shoot me? Your own brother?"
He looks anguished. "Nai, please..."
"You still can't open your gate. You pretend to be human so much you're becoming one. You won't be able to hear them anymore.
"And the humans will still hate you."
"...not all of them."
Knives reaches forward to touch the tip of Zash's gun. "You can keep your humans, Zash."
"And I'll keep our plants."
From where he's touching Zash's gun spreads a spiderweb of blue light, quickly climbing up to Zash's arm and then enveloping his whole body. Zash's eyes glow, too, and even though he tries to fight it, tries to stop it, it's too late. It was always too late. He's frozen, and by the time he's recovered, his brother is gone.
Knives doesn't particularly dawdle to make his way to the plant. He can hear her screaming, there's no way he'd miss it, and soon he's going through the broken down doors (so much for humans taking care of plants, they can't even keep other humans away) and then up the stairs.