Relictivity said:
Crobat has Taunt and U-Turn though. It can also utilitze Brave Brid, so it can act as a threat later. It has to be countered by a Scarf Lead (and admittedly, Crobat is not going to care as much about a Scarf as other pokemon) and it has good defenses to boot. And even if you Trick a Scarf onto it, it has still completed it's main mission, to Taunt. Unfortunately, it isn't quite as limited as you think.
It doesn't have to be countered by a Scarfed Pokemon. I gave the examples of Electrode, who outspeeds and threatens with Thunder Wave, and Regirock, who walls it and it will have to make a tough choice against (if it U-turns or switches out, it risks letting it get SR up, while if Taunts, it risks getting a Stone Edge to the face and either way, it's not actually going to hurt it much).
As for the Scarfers, as I pointed out, there are ones that aren't limiting themselfs by using one that can handle Crobat. Against Crobat, Espeon can Physic, Medicham can Psycho Cut, and Rotom can T-bolt, whereas against other leads they Trick away their Scarfs or do whatever other action is appropriate. Yes, Crobat has Taunt, but that really doesn't matter against offensive Pokemon that can KO it before it does anything, nor against Pokemon like Regirock, who it can't touch and can threaten with Stone Edge/SR depending on what it does.
And against TrickScarf, Crobat won't be in the best of positions either if its first move is a Taunt. The Tricker throws a Scarf onto Crobat, it Taunt, and becomes locked into it because of the Scarf. So, it will have to switch out, letting the opponent then either get a free attack or switch in themself. Only once they come back in, the Taunt is gone and Crobat will be forced to choose a move to lock itself into, most likely U-turn. So, that may not be the best scenario for the Crobat's oppoent, but it's not the best for Crobat either and can be worked with.
Exclamation Point said:
Please do go on. What exactly does he use?
Pretty much, it's just the Toxic Support Regirock from the Analysis used as a lead except without the Toxic;
Regirock@Leftovers/Expert Belt (To avoid LO damage and the hazards of Choice Band, while still getting a boost of attacking power)
Careful
252 HP/252 SpD/6 Def
Stealth Rock
Stone Edge
Hammer Arm
Explosion/Ice Punch/EQ
Edit: Calculating the damage, Regirock does 63.19% - 74.73% to the first Crobat in the analysis with Stone Edge (349 Atk vs 328 Def & 364 HP (100 Base Power): 230 - 272 (63.19% - 74.73%)) while holding Leftovers. However, if it switches to Expert Belt, it does 75.82% - 89.56% (349 Atk vs 328 Def & 364 HP (100 Base Power): 276 - 326 (75.82% - 89.56%)), which means that after that Stone Edge, if Crobat switches out, it again risks SR going up and it dying when it switches back in, whereas if it doesn't and Taunts, it risks dying to another Stone Edge. It does require a bit of prediction, but that's also ture on the Crobat side, and has promising results.