Defeating the Demon Lord's a Cinch (If You Have a Ringer)

Defeating the Demon Lord's a Cinch (If You Have a Ringer) (誰にでもできる影から助ける魔王討伐, Darenidemo Dekiru Kage kara Tasukeru Maou Toubatsu) is a light novel series by Tsukikage with illustrations by bob. The first volume was released December 2016. Yen Press has licensed it for English release.

Plot
Naokatsu Tōdō, a holy warrior, is summoned from an alternate world to defeat a demon lord. Ares, a priest ordered to support the holy warrior, is shocked at the sight of his party members: a mage who can only use fire spells, a sword fighter who just transferred schools, and the holy warrior himself who repeats the same rash actions over and over. Unconvinced that they will succeed, Ares conceals his skill levels and follows behind.