That Time I A Shinigami Got Reincarnated With A Slime

Raiden a shinigami from the soul society, Seeking greater strength he gets involved in the experiment that aizen did on the visoreds to obtain greater power.
During a fierce batlle he uses his Zanpakutō Shingetsu final move paying a heavy price and unleashing a devastating force destroying his body in the process.
He loses some memories but at least succeeded in protecting his soul nucleus and most of his ego and escaping in the chaotic spacetime that occurred because of the attack.
And thus raiden embarks on a journey to a new word but at least this is not his first ride.
After waking up and finding a reincarnating soul in a gargantium like space he hitches a ride to follow Mikami Satoru who had just been stabbed by robber protecting his kouhai into the world of TenSura.