That's cool. I hope somebody will make this.

Make a devil and a HELL demension we need more mobs portals items and tools.
I was also thinking with the mod you can add two more mobs. Dragon And SATIN THE GOD OF THE DEVIL. the dragon can be tamed by Giving it a bone and rotten flesh

Render not so good, maybe make him more in the nether and he eats lava flowing by,letting him attack wouldnt work, maybe if you have food on you of any form he will attack you, but if you manage to quickly give him rotten flesh first itll tame him (but he wont attack for 3 seconds the first rotten flesh fed and the 2nd/3rd will tame him) and possibly make him maybe like six legs but when attacking he will lift the front two forwards and do the iron golem arm movement to attack, Maybe improve the look a tiny bit but nice idea's maybe put ti so the good ol' glowsotne golemn has a wither skeleton with glowstone mouth
& eyes to emit light and it is a obsidian block glowstoen block then wither skull, maybe make most mobs (creepers,spiders,skeletons not attack him but zombies do) and maybe have it then obsidian-ish body maybe with trails of glowstone on it, to make it harder to get and cooler looking, Also a idea is like a Crug, a caveman type guy who will attack a player with his club unless the player drops 1 meat (not raw chicken or rotten flesh) he picks it up and puts it on his club of food :P (what you expect he is a caveman with a kabab) And he will follow the player killing anything (including other players unless they feed him but he will still follow original player) but not attack the original players pets, and skeletons wont harm him much and he cant be poisoned, but you can dye his animal skin cloak thing to different colours with splodges or black on :D that would be real cool! maybe draw that to this to!