Debuff Master

I was pushed to the edge of a cliff with nothing but despair waiting for me.
“I have been watching you for a long time.”
The Level 999 Hidden NPC Deus!
[Do you wish to become the disciple of the Hidden NPC, Deus?]
[YES!]
That’s how I became a Hidden NPC’s disciple!
“Kill them in one blow. It won't look cool if you have to hit them twice, so it has to be in a single blow.”
I was reborn as a being who killed my enemies in a single blow…
Bring it on!
One shot is all I need!
I am the Debuff Master.