MTL - Tomb Raider: Bandit Chief - Chapter 124

Second Awakening? A System? Having lost the battle of the Dark Catastrophe to the demons—spawns of the Dark Gods— humanity is given a chance at making things right once again. Born as a twin into a family of high ranking talent awakeners, Damien Terrace is met with trouble when it is his turn to perform the ritual. After awakening the E-Rank Summoner talent, Damien loses everything to his twin. Exiled by his father to perish away from them, Damien goes through a second awakening that changes the play field for him. Ding! [The God of Summons is furious and has blessed you with a system!] [You have fused with the Mythics Summoning System—A system that only allows you to summon mythical beasts!] [Obtain nineteen Magic Essence Cores to boost your core to the next level!] [Slay 200 more demons to unlock another summon!] Damien’s only option is to evolve!

“Hmph, my dumb big sister is in danger!” A mischievous grin spread across his face. “Hehehehe... this gives me the perfect excuse to finally use this treasure I’ve acquired but never bothered with!” He rummaged through his belongings, carefully selecting various items. “A bit of this... and this... and a dash of this.” Boom! The explosion of energy sent a ripple through the air as he laughed maniacally. “Hahaha! It’s done! Now, all I need is a compatible host for it.” Years later... “Did I overdo it?” he wondered in awe, watching as his creation wreaked havoc, conquering world after world with ease, as though stealing candies from children.

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

"Who touched you?" he asked, his eyes brooding down at her and when she didn't answer, his voice thundered in the room, "WHO?"