This Time, I Choose Humanity!

“You're just a useless Paladin-class warrior, what makes you think that a tank like you will be able to stop all of us?!” “A useless tank? You all are truly inexperienced to be able to say such words.” Ivan muttered calmly as the shield in his right hand vanished and his aura gradually changed. “So what if you're all mages? When pushed too hard, even a shield can turn into the deadliest blade!” ….. Earth was in an era of supernatural normalities. Humans are able to use mana and awaken unimaginable abilities that allow them to be comparable to gods, and dungeons where powerful monsters crawled out from spawned across the planet. In this world where magic ruled supreme, Ivan Castellan, the second son of the Castellan family, ends up awakening a weapon-type ability. He awakens as a Paladin whose duty is to block attacks! However, Ivan remains unfazed by the hateful remarks from others because of his awakened ability. Not just because his family accepted him and he found people who still cared about him at the academy, but because he was in a race against time! Apparently, Ivan was a regressor from thirty years ago and had been reborn into the Castellan family after he was betrayed by his own race because they feared his rapidly growing strength. He was once a part of an alien race that was soon to invade Earth through the dungeons and kill everyone on the planet. Now reborn as a human with knowledge of the future and having the experience of a hundred-year-old alien General, Ivan was set to repay his race for killing him and to repay the kindness of his new family and companions. This time, he would stand with humanity and stop his old race from taking over the planet!