Since KissAnime got shut down I can't search for the title, but heres what I remember. A guys brother is killed in a mysterious tower and his only keepsake the MC gets is his locket that contains all his memories. The MC passes the tutorial with flying colors because of the locket's help in order to get revenge on his brothers killers who were his trusted comrades that betrayed him. He even rehatches a hidden boss that's a snake that orcs worship and starts a war between all the mobs on the floor to get more points. The last thing I remember is he created his own magical circuit of some sorts in 5 days? By the clan leader of the one-horned tribe who is about to go to war as mercenaries. He also has a huge egg that is supposed to hatch into something crazy but because the MC's only goal is revenge and has no true desire it won't hatch.

Any help is greatly appreciated!

Just a guess but maybe Second Life Ranker?