Instant Death and Destruction of the Weakest Magician is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on ManhwaZ fastest updating comic site. The Summary is
Arc and Lean are aspiring adventurers. Upon appraisal, Lean is revealed to be on the level of a hero, with the level cap of 30 and the skills [Sacred Magic] and [The Goddess's Blessing]! However, Arc has an instant death magic with a level cap of... 1?! With his instant death magic, he'll becomes embroiled in a national crisis that shakes the world!