Atm I dont see this as a problem, But it would be hell if warpstone was removed (as it seems like it will be) since Dark would still be abel to do it with Erebus but Light wouldnt, dont think Cloak of Night or the Artifact got enough range for it.

The Cloak of Night does have the range, as that's the only item I've ever used.  I've thought about getting a warpstone for double jumping out of trouble, but figured that would be a little over the top.

Here's the cheese part:

In a 1 v 1 on Crucible - Erebus warps to portal flag (optionally uses invincibility item so towers don't hurt).  The opponent ports or walks back to attack Erebus, who retreats by batwarping back across the gap.  If opponent follows across the gap with warpstone then Erebus can warpstone back to portal flag and opponent is stuck waiting for warp or port cooldown.  Erebus locks portal and teleports out.  If opponent doesn't follow then Erebus can go farm until opponent is back at frontlines.  Time it right, rinse, repeat, and you pretty much lock opponents to their base with minimal xp and grunts, while you continue to level... 

Erebus will always have one warp more than the opponent, and on this map it can really make a difference

Edit:  Cloak of Night + Warpstone + Batport exacerbates the issue - and yah, it's definitely worth getting Cloak and Stone for those lightning strikes

Well most of this conversation is about to become moot with the removal of the warpstone in 3B.

Only if the devs tweak other warp mechanics as well.  If they simply remove warpstone you will see this strat becoming alot more powerful for Generals and especially Erebus, with no counter available for Assassins

Warpstone will be 3500g and 20 yard range in 3B, so it will still be there.

And oh rave, you cant doublejump with Cloak of night and warpstone, they share the same cooldown.

Good to know before I go try it.