I don't want to spoil so I'lm just gonna say that you gotta read the novel. It's great :)
Spoil for me :’)
Beru (the ant king) will be his badass loyal pet lmao
That dark moment is somewhat related to his power. It would be explained further ahead. And dont worry about Beru "Ant king" he is completely loyal to him if the manhwa will follow the Light Novel. And Beru will be his most powerful summon.
Maybe he should have left the ant alone...that dark moment that had him confused dosen't look like something to brush off....what if it gains power from eating even after it's dead!?!?!!!