Iruda of Wrath

Iruda of Wrath (憤怒のイルダ Fundo no iruda) is a boss in Succubus Puttel associated with one of the seven deadly sins, specifically wrath (ira in Latin).

Strategy
Iruda begins the battle with Deadly Sin: Wrath, which doubles your attack and halves your defence. It's therefore best to take advantage of this to defeat her as soon as possible, before she can do the same to you. One strategy that might help is to use all of the Endure: [X] skills (i.e. the skills that greatly reduce damage from a specific element for 1 turn) in the menu before challenging Iruda. This will cause you to take far less damage from her first attack.