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

Defeating the Demon Lord's a Cinch (If You've Got 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 Japanese light novel series written by Tsukikage and illustrated by bob.

Plot
Ten years have passed since the Demon Lord Kranos declared war on mankind. As the situation grows desperate, the Ruxe Kingdom summons a hero from another world to stand against this threat. Assigned by the Church to join the hero's party, a battle-worn priest arrives to fulfill his obligations but is shocked to find that his companions are utterly inept! A mage who can only use fire magic, a swordswoman recently defected from her father's fighting school, and a hero obsessed with women?! With an average level totaling just 15, there's no way these novices are capable of taking down a demon lord! But a job's a job, so it's up to the man of God (who thankfully has power to spare) to support these buffoons from the shadows. With an extraordinary healer on their side, defeating their target will be a cinch! ...Hopefully.