Pokemon Name: Rotom-F
Lead Type: Offensive Lead
What it does: Outspeeds a great many pokemon with a Choice Scarf, cripples the ubiquitous Stealth Rock support leads with Trick
Why it is good: Great SpA, STAB Volt Switch and Blizzard. On a Hail team, Blizzard will never miss, so you get 120 power with no downsides.
What counters it: Anything that hits it super effectively before it can Volt Switch. Things like Scarf Sawk, for example.