Greed Series

The Greed Series is one of the seven sins and also one of the two sets from the Curse Series claimed by Ren after being manipulated by Malty shortly after losing all of his companions during the assault on the Spirit Tortoise.

Overview
Due to his misconception of the reality he was in, Ren treated everything like it was a game he had played in his world. However, he had sorely underestimated the Spirit Tortoise's power which got his companions slaughtered. When he finally realizes he is not simply playing a game, he breaks down and tries to cope with what he's done. Naofumi then tries to console Ren but is interrupted before he can finish.

Before Naofumi can finish his talk with Ren, Malty and Lesty appear and takes advantage of Ren by blaming Naofumi for his misfortune. Ren teleports away with the two women who convince him to train with Mald. However, finding him difficult to manipulate and less useful than expected, they take all of Ren's belongings and leave the next morning. In discovering the betrayal, Ren unlocked the Greed and Gluttony Curse Series. Both are unlocked by his desire to get stronger which he believed is the key to being success.

The third time Naofumi meets Ren, Ren has become the chief of a notorious bandit group. Refusing to be apprehended, Ren tries to kill Naofumi and company in order to harvest experience and equipment to get stronger. Eclair ends up defeating Ren who then gives in and joins Naofumi. However, he is consumed by the side-effects of his two curse series. As a side-effect of the greed series he was cursed so that any object he touched would degrade in value. Fortunately, since he did not utilize the curse series extensively, there were negligible personality side-effects.

Trivia

 * While Ren wanted to get stronger for the sake of getting stronger, Naofumi only wanted money as a means to an end which is why Naofumi did not unlock the greed curse series.