The best combos I discovered mid screen is b3, j3, j2, 2, power fist (35%, 39% with meter in power fist) which can be used as bnb because it deals a fair amount of damage it is pretty easy and very consistent. If you replace it with b3, j3, j2, 3, power fist (36%, 40% with meter in power fist) it adds 1% of dmg but is not that consistent as the 3 tends to whiff some times and it is harder to land. So stick with the easy one!
In my opinion 35% to 39% mid screen BnBs for a heavy zoning character is pretty nice!
The only downside of these combos is that u ll have to land a back 3 to get them..