Game Invasion: A Necromancer from the Start

After transmigrating into a world invaded by a game, Su Wan awakens as a necromancer. While others summon one skeleton, he summons a hundred. While others need three days to level up once, he reaches max level in an hour. When he floods the Abyssal Tide with a sea of skeletons, the whole world is stunned. Even more shocking is his younger sister, an SSS-rank Eternal Seraph, who's an obsessive brother-con. “Big brother is mine. Any woman who gets close to him will die ♡” The campus belle confesses? She gets teleported to the North Pole. A Valkyrie challenges her? She beats her until she calls her big sis. The Elven Queen seeks a political marriage? She blasts her off Earth with holy light. Until nine stunning women stand behind Su Wan: An icy sword immortal, a battle-crazed big sister, a mechanical girl, a nine-tailed fox, a ghost princess... His sister smiles. “Fine, big brother can have a harem, ” “But I have to be the main wife!” Su Wan: “Um... can I say something?”