Demon Slayer: Trading Aizen a Zanpakuto from the Start

My account is toast, so I reincarnate into a new one with an absurdly lucky starting hand: four kongs. After transmigrating into the Demon Slayer world, I’m attacked by demons, and the [Dimensional Trading System] activates. I make a cross-world deal with Aizen, who has successfully conquered the Soul Society in a parallel world. Bored out of his mind, Aizen says that as long as Su Ming provides enough demon specimens, he’ll lend him a hand. Zanpakuto, Flash Step, hand-to-hand combat, Kido... Tanjiro: Mr. Su Ming is so kind. He always does his best to train me. Shinobu Kocho: Su Ming is reliable. He puts me at ease. Kyojuro Rengoku: Mm! Su Ming is incredible. I’d be dead without him! Kagaya Ubuyashiki: Su Ming’s arrival means the Demon Slayer Corps can sound the call to counterattack! Akaza: Su Ming is a worthy opponent. I’ve never seen such an unusual martial art in all my centuries! Muzan Kibutsuji: Why is there another monster like Yoriichi Tsugikuni among humans, now that he’s dead! When the little happiness in his hollow heart is destroyed, Su Ming, realizing that death is near, is consumed by a boundless hatred of demons. The thousand-year blood feud between humans and demons is destined to end with Su Ming’s arrival in this world. My name is Su Ming, and I am fate itself! Muzan, it’s time you came out and got some sun!