edit2: OMG IT KNOWS ROAR! crap now im scared =[ if i get a shiny should i use my only masterball?
I know just about everything around every situation like this, so here's my advice:
For chaining this one, obviously have a Pokemon that's high-level and can kill them in one hit. Roar makes it go last, so Speed shouldn't be a matter but you should be faster than it anyway.
If you get to 30, 40, whatever and shiny grass comes up.... What to do, what to do. It'll just Roar you away if you try to weaken it, so the best bet is the best Pokemon for catching Pokemon: Breloom with Spore + False Swipe.
It's still very risky.
Why? Spore, Swipe, HOUNDOOM woke up! HOUNDOOM used ROAR!
So what's the best thing we can do?
Counter Roar with a Pokemon Ability.
It's called
Suction Cups, and it makes it to where the Pokemon can't be Roar-ed away.
3 Pokemon have this ability.
Lileep
Cradily
and....
Octillery.
Octillery is slow but powerful, and it type-trumps, so you could use it as your chainer for Houndoom and other Pokemon that know Roar or Whirlwind.
Let's see, what can Octillery do to help you?
Surf and other high PP attacks will help if you decide to also use it as a chainer.
Shiny Houndoom appeared!
What to do:
Well, don't hit it..... CONSTRICT it. You could try that move out on a previous nonshiny Houndoom to see how much damage it'll do. You can use it to chisel away at Houndoom's health.
Octillery doesn't learn a sleep move but it does learn Thunder Wave so if you want to use that you can.
Suction Cups are Roar B Gon.
You can also use a similar strategy with Cradily if you'd prefer to use that one. :)
Good luck!
As for me, I'm trying to get RID of those Giveaway shinies I got a while back. The Mew is so hacked, I can't even trade it on GTS and on PBR it shows up as a bad egg -- we will NOT have this on my game!
I'll probably end up releasing it. As for the others, Chimchar's been GTS'd, but it's the only one so far. I'm going to see if my friend Anthony wants Turtwig but it's the same thing as Chimchar.
I'm wanting to keep Squirtle, Cyndaquil and Steelix but I'm gonna send them down the road too.
I got Explosion which is how I found out about the bad egg Mew, I was uploading my Pokemon to PBR and it said I had a Pokemon switched to Bad Egg which made me go "WTF!?" and then I checked and sure enough it was the Mew, I didn't save PBR, I just turned it off.
I don't think I'll be going to any more Giveaways.
Even if the person was sincere and was only collecting them to begin with.