Guia pro noob do Coringa

In my little expericien... Snipers are paper at all... 30% more dmg won´t doom you... You will die if someone get you... I´m planing test this MoM in mid after SB... Yes, I like Sb in Early/Mid :D

MoM is for attack speed. you can also use it for escape or chasing because of movespeed increase. but is risky.
May are just scared about the 30% increase to the damage taken but if you use MoM properly, it's really worth it.

Sniper also has a good attack range, just position yourself well and nobody will hit you.
for those with good mobility(blink/morphling) make sure they use it before you show up so they won't be able to close the gap in an instant.

The build is good, but why Mask of Madness? You die really fast, with Mask of Madness you die even faster, try a Helm of the Dominator instead, it gives you lifesteal, damage and armor. It's better.