Obviously, because I put these 'rip off picture' as you say and expect decent arguments which was my mistake. These similarities are not as subtle as you point them out to be and from an objective point of view, this is way more than an inspiration. You can copy fighting styles and inspire yourselves from myths, legends or other popular personalities but just copy and pasting from other mangas is what is called a cheap rip off. However you try to justify it, there are things that are plain obvious.- Okay for first picture, that would make for now only 2, for OP's 700+ chapters and FT's 300+ chapters. That's not rip off.
- The manga is called Fairy Tail. In some mythologies, Fairies are water beings that lives in the see. Some of them are similar to mermais, while some are exactly what Mavis is. Rip off? No!.
Really. I always found odd these posts like "I won't waste my time". If you don't want to waste, than why did you came here, you though you will come to FT's section leave a couple of "rip off picture" and go... no..