[@raijinslayer] Good to know. I did explain in my DeS Notes that it gives a huge power boost. An example of it would be Gray's Ice Make having legit destruction capacity.
[hider=LOOK at this pics and you will learn][url=http://www.mangareader.net/fairy-tail/506/16]Naruto vs Sasuke[/url] and [url=http://www.mangareader.net/fairy-tail/506/17]DeS vs Demon[/url]


[url=http://scontent.cdninstagram.com/t51.2885-15/s480x480/e35/12960090_505245062992943_1199014333_n.jpg?ig_cache_key=MTIyODUxMjY4MDI3Mjk2NzM1MA%3D%3D.2]Ice Make: Silver[/url]

[url=http://vignette2.wikia.nocookie.net/fairytail/images/e/ef/Frozen_Sand_Golem.png/revision/latest?cb=20150812123656]Effects[/url]

[url=http://vignette2.wikia.nocookie.net/fairytail/images/e/e3/E.N.D._vs._Gray.png/revision/latest?cb=20161004192916]http://vignette2.wikia.nocookie.net/fairytail/images/e/e3/E.N.D._vs._Gray.png/revision/latest?cb=20161004192916[/url]

[url=http://www.thebitbag.com/wp-content/uploads/2016/08/fairy-tail-499-gray-empowered.jpg]Effects of Insanity[/url]

[url=http://www.mangareader.net/fairy-tail/506/9]These marks against the highest caliber demons and what should it be in the RP[/url]

[url=http://www.mangareader.net/fairy-tail/506/10]THESE[/url] and [url=http://www.mangareader.net/fairy-tail/506/11]AND THESE[/url]

[url=http://www.mangareader.net/fairy-tail/506/13]THESE![/url]

[url=http://www.mangareader.net/fairy-tail/506/14]OMG[/url]

[url=http://www.mangareader.net/fairy-tail/506/15]OMG!![/url]

[url=http://www.mangareader.net/fairy-tail/506/18]FINAL CLASH[/url] and [url=http://www.mangareader.net/fairy-tail/506/19]OMG![/url][/hider]
These manga spoilers are for those who want to know how strong a Devil Slayer is, I know you're no Gray but I am showing the effects of those markings and insanity as well as whatever power boosts.