All righty, serious time!
I'm trying really hard to stay objective here, but Tornadus-T is one of my least favorite pokemon, so that bias is likely to show just a little. At a glance, base 121 speed with nasty plot is great, but looking deeper, it's ability regenerator and how easily it can U-turn out for momentum does not harmonize well with set up sweeping. It's definitely possible it'll only benefit from the new role, as it could possible scout around, then clean at the end, but its coverage leaves me less than convinced as of right now.
Steel Avalugg scares me. A general counter to all physical pokemon? Yes please. Still wish it had recovery, but if that were to happen, I'd quit pokemon.
Intimidate Milotic, seems a little more realistic. Automatic -1 atk for whatever you switch into leaves you open to invest in special defense, meaning you'll check a lot. It can spread status, shut down sweepers, tank, and who knows what else. I really like this fish, even if it's not as flashy of a change as Avalugg.
Poison/Steel Weezing is pretty obviously great typing, and with its ability it's only better. WoWing anything that tries to hit it, Pain Splitting anything that tries to wall it, this is a great role player that would be interesting to use.
After initial thoughts, I'm leaning towards Milotic, but there's 3 great physical boons here, so I'm really interested in how this conversation goes.