User blog comment:Miskos3/Fairy Tail Episode 252: Tartaros arc: Gray vs. Silver, Review/@comment-4449950-20150926115915/@comment-4449950-20150926124501

Lol, found the reference myself. It was an interview question Mashima got:

Q: In Fairy Tail, often the "villain" characters get redeemed in one way or another. Do you believe in giving people second chances and that anyone can be redeemed?

A: Absolutely. However, I value life heavily, and that's something to keep in mind. Sometimes I depict where a character passes away, but then it turns out they actually hadn't, but I never draw how someone who was actually already dead coming back to life; that's not something that I depict.