The supporting character's harem is very normal - Chapter 52 Their relationship is too complicated.

The existence of a magician is to understand the truth of the real world. Saleen Metatrin, an ordinary magician, initially wanted to change one’s mind and destiny. During this, he went through many situations and phases in his life.

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates

I am the sword.
Killing a man amidst a thousand miles, no one dares take ten steps.
Killing a man amidst a thousand miles, no one can take ten steps.
Killing a man amidst a thousand miles, ten steps? Not possible!
I am the sword, the sword is me,
On the path towards heaven, each shall wield their own.

Heed my call! O’ Dragon of Eternal Sin, the Progressive Disaster, the Forerunner, the Land of Eternal Peace, the Flames of Soul Burning, He Who Owns The Deep Soul, the Sound of Origin, the First Cause of All Things, the Principle of Circles… o’ great Negary, your servant calls for your return!