Mid Omni?

I counter him with Naga Siren, just Sing until his ult is over and focus down him with Bloodthorn, also she is a good Diffusal Blade builder so its ok you buy one

To be honest, it's more like he's situationally the best late game support in the game, and situationally a complete dead weight.
He's got the best damage scaling on a support in dota. Yes, he can out-damage a 6-slotted Medusa which is hilarious. And solo kill any carry without an escape mechanism. But he still has two major flaws :
- no stun
- no teamfight-winning skill

He's definitely not ****ty and he is underrated as hell. Still, there are some games where I wish I had a Lion or something, even in the very late game. He's the kind of hero who really shines in some games and feels completely useless in some others. Just by looking at the picks, that is. Kind of the Rubick syndrome.

In a few words I'd describe him as an anti - low mobility carry who's also a walking Euls.

OT - the thing with Shadow Demon is, it's pretty hard to get much done without your team - you have no real slow or stun, so you're reliant on people being smart enough to land a skillshot, or having a clue just how good his damage boost is.

Most of the SD players I see are terrible - like the guy recently who coming in on me Fiend's Griping an enemy, goes "hey, you need this guy Disrupting, right?". Hell, why would I want up to 50% extra damage when you could just save them instead.

Back onto Omni, there are some really good and bad things about the hero, I would agree on Naga Siren as a counter though - that guy who begged for a Repel is gunna regret it...

Did some brief research: since Repel can be removed by basic dispels, I think that Spark Wraith will in fact purge it despite the skill typically not going through magic immunity. So Arc Warden and his ridiculously low cooldown dispels may actually be an insane counter to Omni, considering it also removes Guardian Angel

https://www.reddit.com/r/DotA2/comments/4iezi1/til_spark_wraiths_are_unable_to_purge_off_repel/

http://i.imgur.com/Pu5rorV.gifv

Visibly no, Spark Wraith doesn't purge repel.

That whole purge/repel thingy is pretty messy anyways since it's different rules for each specific skill.

Well then that is clearly the Arc Warden buff we need.

Making him a completely unfair counter to one specific hero in the game and still be terrible otherwise? Sounds like something OSFrog would do, yeah XD

But seriously turn him into an INT hero (since his best items are INT items anyways) and replace the silly easily disabled evasion from Magnetic Field with something actually useful like an armor bonus. Also buff his BAT a bit.
Of course there's the lazy way out of just buffing his AGI gain to 3/level but I don't want another Terrorblade

What about this ? Magnetic Field now traps everyone who pass on it, much like a chrono which you can still use itens and abilities, i think a magnetic field should work like this, remove de evasion and stay with the AS bonus

Coupled with making the hero a int one Necrobook and Bloodthorn would be viable as hell

Oh hamster, you really know your arguments. But you make many assumptions.

Arc can counter him in lane. Mid arc against mid omni, it's.like playing a negative game. Mid (I know it's a lot, overstated to some extent) you have 8 free diffusal charges

Techies offense is the way people should play him early. Further, you need to stop underestimating his land mines, his q. Dump 30to 40 in one place, Omni's ulti is the only thing to stop it. Techies doesn't necessarily counter omni, he makes the game annoyance which makes people RQ. XD(we are talking about puns we are)
Then there is techies mid. Works well against the bastard. You could net a kill or two with suicide early also
His W does jack**** for him.

AA is a strategic pick to go with a mix draft of physical and magic damage, he can't just repel, kills his heal his greaves and amps all nukes, that's something.
If omni ever comes to lane against him, a single point in in AAs E will teach omni what to expect, omni will get kited so hard with vortex he will never reach his aghs.

Cent yeah is a trade-off, but I was talking more on grounds of using his ulti to disengage. Which means you need a second instigator. Draft problems yeah.

And I don't think an omni will get a chance to buy aghs if magnus kill all enemy team heroes if omni hangs back, or he gets RPd if he stays in the thick. If only cleave worked on guardian angel I could buy some bloodthorn and kill the poor fellows who grouped up in rp

Edit: stupid autocorrect

I forgot biggest counter

Invoker
Tornado makes omni cry