i've been running a variant of this on my stall with great success, putting knock off on the last slot. It's both a great wall (100 / 100 bulk is amazing, living +1 mega ttar's crunch) and great at breaking opposing stall teams (100 spe taunt is too). The only thing it can't really touch is fire types and gliscors after the first switch in.non-Defog support
Mew@Leftovers
EVs: 252 HP / 148 Def / 108 Spe
Nature: Bold
Alternate spread: 252 HP / 108 Def / 148 Spe, Bold nature
Alternate spread: 252 HP / 152 Def / 104 Spe, Timid nature
-Taunt
-Soft-Boiled
-Will-O-Wisp
-Stealth Rock/Psychic/Ice Beam/Fire Blast
Originally i ran defog over knock off. But heatran would switch in on it for free and force me to stay and taunt if i didn't want it to get rocks, getting a free 30% chance burn.
Without leftovers, tran loses its recovery and eventually dies, so this is not indefinetely walled by heatran anymore. Also, non-fire types burn down much faster after lefties have been removed; regenerator being the only kind of recovery they retain after taunt.
Edit: i have been running only 16spe which outspeeds adamant bisharp, not sure if this is optimal.