In my opinion, Honchkrow's current best set and the one I will be discussing is:
Honchkrow @ Life Orb
EVs: 252 Atk / 4 Def / 252 Spe
Nature: Adamant
Ability: Moxie
- Substitute
- Roost
- Brave Bird
- Sucker Punch
Based off of prior knowledge, +0 Honchkrow 2HKOs:
Relaxed 252 HP / 252 Def Quagsire
Bold 252 HP / 252 Def Spiritomb
Bold 252 HP / 252 Def Cofagrigus
Relaxed 252 HP / 252 Def Ferroseed
Those are some of the bulkiest physical walls in RU, and Honchkrow 2HKOs them. Still this does not make Honchkrow ban worthy. Many common Pokemon in RU can beat it, including: Aggron, Klinklang, Steelix, Regirock, Rhydon, and even Stunfisk :p. Another honorable mention is Entei, who is able to evade Sucker Punch with Extremespeed. But good player will not Sucker Punch if they have a sub up, or they will switch out from Entei if they do not. The only reason Entei can force Honchkrow out is because of Honch's pittiful base 71 Speed. This severely hinders its ability to sweep because after the sub is broken, most Pokemon can outspeed and set up a sub of their own (Sceptile, Rotom, Moltres) or take Sucker Punch and KO (Sharpedo, Hitmonchan, Hitmonlee, Kabutops). Even if you don't have one of these Pokemon, you are still able to play around it.
Honchkrow is weak to Stealth Rock, takes recoil from Brave Bird and Life Orb, and takes damage from substituting. This will make Honchkrow's life span short, even with Roost, reason being: it can't take a hit. If you Roost on something, you lose your sub, if you attack, you take damage. I've been testing a stall team without a Honchkrow counter (no, I wasn't running Avira's stall). I tried the Pokemon mentioned above, but they got 2HKOd, yet I was still winning against Honchkrow. Why? Because it took so much damage from recoil, I only lost 1 or 2 Pokemon max. Ferroseed is on my team, and even though it takes 60% from Brave Bird, Honchkrow takes damage from Rough Skin, Life orb, and a huge chunk of HP from using Brave Bird.
Overall, Honchkrow should keep its place in RU. It is very easy to beat if you play it right. If you're that worried about this Pokemon, just use a bulky Steel or Rock type Pokemon, I mentioned the main ones above.