[@Altered Tundra] It's me Masaki Haruna, just got a different name.

[@Quatro] We are vigilantes.

There are other races too. But for now, there are devils. In which Leslie answered for you.

[@BurningDaisies] No other races for now. There are devils. Leslie answered it.

Okay.. woah.. guys slow down with the slayers.

God Slayers have a possibility of existing but we're iffy on that subject for now [s]apart from the fact their magic is useless fodder trash and only Chelia is the best God Slayer[/s]. Dragon Slayers do not since they are extinct to begin with as we're basically basing the story from canon, many many years later. We banned Dragon Slayers for the same reasons as Uchihas to Naruto RPs.


[color=ed1c24][h1]Devil Slaying Magic Explanation. DO NOT EVER TL:DR me on this. EVERYTHING IS MANGA EVIDENCE.[/h1][/color]
Devil Slaying Magic is a lost magic designed to kill devils/demons. Its wielders are immune to their own element like other slayers but what differentiates them from other slayers is the fact that, they have powerful eyes that can gauge demonic energy and exploit its physique/weak spots. 

[hider=Gray's eyes changes when using DeS'M][img]http://img04.deviantart.net/1f9b/i/2014/244/1/5/fairy_tail_398_eye_of_the_devil_by_iitheyahikodarkii-d7xkjie.png[/img]
[img]http://img15.deviantart.net/f839/i/2014/244/4/4/gray_demon_slayer_by_eclair28-d7xj1ps.jpg[/img]
[/hider]
His eyes are red in the manga though while in the anime it's purple.

[hider=RESISTANCE TO CURSES][img]http://ptanime.com/wp-content/uploads/2015/02/Fairy-Tail-411-Gray-e-Natsu-Sobrevivem.jpg[/img][/hider]

Limited. DeS's can absorb curses and resist it but it doesn't mean fully blown immunity. It still can kill them however.

[hider=DeS Marks][img]http://vignette1.wikia.nocookie.net/fairytail/images/a/ab/Gray_intercepts_Ajeel.png/revision/latest/scale-to-width-down/300?cb=20150812122644[/img][/hider]

The tattoos are the after effects of absorbing too much curses. Too much as in even if it's just one, it's powerful. THE TATTOOS GIVES A HUGE BOOST IN MAGIC RESERVES, TENFOLD FOLD OF STATUS than in base.

[hider=Ice Make got Boosted][img]http://vignette2.wikia.nocookie.net/fairytail/images/e/ef/Frozen_Sand_Golem.png/revision/latest/scale-to-width-down/170?cb=20150812123656[/img][/hider]
^THIS IS THE EFFECT. IT'S A NUKE.

Also not forgetting. Devil Slayers element is vastly different. It has instant flashes. The element can never be thwarted by any means. Natsu can't even melt Silver's ice.

However this is debunked. A Mage with a high mastery of their own magic can beat the Devil Slayer's "INSTANT FLASH".

[color=ed1c24][b]What is Instant Flash?[/b]
[/color]A term I created. Ice is weak against fire but as Devil Slayer, ice beats fire due to its nature of the magic. But if against a high caliber of mage with high magical power of fire, they can melt the ice. Same will apply to any element you guys will use. 

E.G INSTANT FREEZING, INSTANT BURNING, INSTANT WIND THINGY, INSTANT WATER ETC...

This is the weakness.

[color=ed1c24][b]WEAKNESSES[/b]
[/color]I am too lazy to give a picture but Leslie already explained it to you. Slayer magic is brute force while a non slayer who uses the same element have more creativity. A Devil Slayer like any other Slayer sacrifices creativity aka manipulation shape of element over DESTRUCTIVE POWER.

Devil Slayers also goes to the point of insanity because the magic corrupts them the more they use it. It's like saying the more Mangekyou Sharingan is used, the faster you go blind.

One way to prolong the insanity is... I'M NOT GONNA TELL YOU. But Gray has ice make and molds Devil Slayer Magic. You guys get the point.