Reincarnated With an S-Rank Summoning System

Waking up in a strange forest with no memory and a bizarre game-like menu, Kelvin quickly learns he's been reincarnated – a cosmic apology for a god's fatal mistake. His compensation? An S-Rank Summoning skill, allowing him to contract anything and make them overwhelmingly powerful, alongside S-Rank Appraisal and double growth rates. His first \"subordinate\" is none other than Melfina, the very Goddess of Reincarnation herself, now his snarky, invisible partner. To avoid attracting unwanted attention, Kelvin registers as a humble Green Magician. But with a single slime transformed into a combat monster and the Goddess of Reincarnation waiting to be physically summoned, how long can he hide his monstrous power before the world discovers the true extent of his cheat?