Hey everyone this is FvR-JNizzle10 or MRJNizzle10 from youtube. And this, id mt my top lane guide on Atrocitus.
Currently he is one of my favorite champs to play because he fits to my aggressive play style and his tanky skill kit.
he is a great top laner but you can use this build to support as well. One of the biggest things I had to overcome is as a tank, dont be afriad to lose health...afterall you are a tank. 2nd, Atrocitus's ult should be used when the fight/team fight starts since it will increase you damage output. 3rd I like to think of his metor drop to be more of a utiliy then a damage power, if you get the kill with it, more poer to you! 4th his W give him damage reduction for a short time so try to time it when the enemy goes in on you, I can't count how many times it saved me from a gank cause their basic attakcs were reduced. 5th don't be afraid to dive or go though the enemy pack to get to the carry. it really helps your team if you take the damage while they get the kills. 

So overall I think Atrocitus is a great tank top laner then can still deal a great amout of damage while providing enough CC to help the carrys, well carry.