Zero no Majutsushi: S-Rank Yuusha Party wo Zenryoku de Support Shiteita noni Tsuihousareta Saikyou no Majutsushi wa Party Kyoufushou ni Natta node Zenryoku de Ohitori-sama Musou wo Hajimeru Koto ni Shimashita @COMIC

Rude, a magician belonging to an S-rank party, is expelled from the group due to the selfish actions of the hero, Tran. Betrayed by his comrades and heartbroken, Rude abandons the town he had been staying in and sets out on a journey to the neighboring Roland Empire in search of a new home. While on his journey, he defeats a band of thieves attacking a slave caravan. Then, unexpectedly, a beast girl who should have been freed pleads, “Please... I want you to be my master!”...? The strongest mage, abandoned by his comrades, becomes unstoppable in his new home! The Ultimate Heroic Fantasy! (Source: TO Books, translated)