NIKKE: Killing Monsters Drops Loot, but Why Is It Mechs?

I opened my eyes to a bag of oranges, a phone with no battery indicator, a Tang sword, and a radar in my head. Before me lay a ruined wasteland. I had no idea where I had transmigrated to. I fled in a panic. "Damn it, you son of a... why the hell are you still chasing me, Retch!" A thrilling counterattack. Wait, killing Retch drops supplies, stat points, and even [Resolute Armor]? Don't tell me you drop mechs too, you little punk!?…[Welcome to the world of Nikke!] [Commander, the Ark isn't full of maggots for me to eat!] [You have received a message. Please check it as soon as possible!] "I am…T-T-T..." "…We are facing a crisis..." (Early on, it's Nikke and the protagonist's own body; later, it's giant mechs. Punch Retch, kick the Ark, and cuddle up with Nikke at night.) (The mechs come from Iron Saga. There's a little medical aircraft below and mechs capable of crossing the multiverse above.)