I am one against Honchkrow in UU, but I think that you're stopped by any fighting pokemon ever. Let me remind you HONCHKROW IS AS SLOW AS PASTE. meaning that any pokemon that outruns your bird will probably eat it for breakfast.
Or what about a sub-puncher? What about Sub-Seeders?
What about any pokemon who can set up on this set? This isn't that exciting to me. This doesn't seem broken.
SubPunchers in UU:Aggron and Kangaskhan.
HP Fighting ruins them both.
Subseeders in UU will be loath to switch in for fear of Drill Peck, and even if they do switch in on a screech, you can deal with them...
They're not going to stay in and seed, plus the subs are easily broken by Pursuit once you've screeched them. And they really aren't going to be healing enough from Honchkrow's HP to last forever. And most of them use Energy Ball as their main attack. Just how much is that going to do to Honchkrow? They're not getting around it any time soon. The defense is halved for God's sake, and you have a 120 BP Priority attack if they're attacking.
And lol@Pneuma.
EDIT:@Thunderpup Orly? They're setting up on you with half their defense? And which part of Sucker Punch is a priority attack allows faster pokemon to eat it for breakfast?