You die fast and kinda need BKB- if farming well and going for late game something then Butterfly and Satanic are much better- you won't get them both at first or for nearly as cheap, but you'll get them eventually. Battle fury first lets you farm up whatever you need.
"Kids these days huh? Can't live with them, cant chop them up into tiny pieces." -Mcbeth -Crabdom Ambassador.
Generally a crap item that you should never build unless you can't afford one of the dozen better items.
But if you are that underfarmed you will probably lose anyway.
Also no offense, but lol at it being a good escape tool. "I'm running away, lets just make sure I take double damage from everything first...."
You don't take double damage from MoM, and movement speed is a great deterrent from ganks. Ever heard of sprint? Positioning over EHP, meaning if you can't get out you're most likely dead anyway. Mask of madness is definitely not a crap item, you just have to use it correctly.
Too many hypothetical situations here. Coupled with his R, mask of madness isn't a bad option by any means. Sure, build battle fury as well- but darting around inside your R bursting kids down with +100 attack speed is nothing to laugh at.
It also has synergy with Backtrack in that 130% damage is turned into 97.5% damage, and Time Lock with the attack speed.
I don't like it though because I feel like paying 1000 gold for an active that has a drastic downside is pretty not good, but it is pretty good on Void because it has four synergies with all of his abilities. And as Maglev says, it is really good for escaping.
You'll see - Eternal love, that's what this is This feeling that I just cannot resist...OD