I don't see offensive Leafeon dropping though, Heracross has weaker physical defense than Venusaur (80/75 vs 80/82) and Leafeon already OHKOes Venusaur with +2 Lefties Double Edge, so against 4/0 Heracross without a LO boost:
97.7 - 115.2%
Leafeon can also easily be EVed to be faster and will always OHKO with Aerial Ace, so it can come in on any attack bar Megahorn once (CB Close Combat obviously hurts -
75.3 - 88.8% vs 132 HP Leafeon) and outspeed and OHKO back. Obviously not a counter, just a check. The thing about Heracross though is that it's a lot easier to revenge kill for offensive teams than Gallade was - you have the pool of fast frail Ghosts/Psychics that can come in afterwards and revenge kill since it has no Shadow Sneak, and that exploitable 4x Flying weakness means that if you're team is having considerable Heracross problems, you can easily put HP Flying on Rotom or something and effectively check most variants.
Thing about Heracross is that it isn't that fast, and while it hits like a truck, it's also very vulnerable to entry hazards and being worn down by LO/FlameOrb damage, and is not too hard to force out for an offensive team. Rhyperior and Alakazam are all pretty much equally as hard for offensive teams to switch into as Heracross. I'm not saying it's not broken or it is becasue I've most definitely not played with it enough to say one way or the other with any credibility, but I'm just keeping an open mind. I like to "accept" something is UU and then assess its BLness.
EDIT:
erazor said:
If/when (let's be honest, when) Heracross is banned, it's certainly not going to be for his sweeping prowess. It's going to be because nothing can take a hit from this bug. Seriously, forget guts SD - Nothing can switch into a CB/Plain Guts Megahorn or Close Combat. Mismagius? Raped. Rotom? See Mismagius. Weezing? The best switch in yet... but dies to Guts Facade. Moltres - only Subroost though - can switch in and survive Close Combat barely, but is forced to Roost. This can go either way - if Moltres Roosts and Hera switches in, Hera wins, but if it stays in and Moltres uses Flamethrower, it dies.
Playing against choice hera becomes a prediction game then - while it hits like a beast, there are still Pokemon that can come in on some or all of its moves and pose a threat. The Choice versions aren't nearly as big a threat for defensive teams as SD, since Weezing / Nidoqueen can come in on all the attacks, and there are viable Pokemon for offensive teams that come in 3/4 of the attacks (Moltres, Aggron, Arcanine, Scyther, (Golbat), Nidoking, etc). Heracross has the
capacity to be impossible to switch in, but with experience and player analysis you can tell if they like to open with stone edge or megahorn or whatever. It's way too early to be saying "if/when (let's be honest, when)" atm.