I Don't Have The Qualities to be a Saint, So I Decided to Aim to be The Last Boss! is a Manga/Manhwa/Manhua in english language, Drama series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Rina Amakusa is exhausted from her job at a black company. Guided by a voice, she enters the world of the game she loved and becomes a saint. She repeats the loop and tries to save the world, but when her beloved character is killed, her love for him turns to hatred. When love and hatred change her from a saint to a last boss, the "revenge" otherworldly fantasy begins!