Well, I'm relatively new to the CAP concept but i'm very impressed what all those CAP rounds have delivered as final products. I'm aware the TL has said he wants to focus our effort on Offensive/Support roles as we make the assumption Stall/Wall ones are "safer", but maybe we are aware that is easier destroy than build. A sweeper/wallbreaker job is to shatter any opposition the foe can offer towards victory, and in this aggresive 5th gen metagame that can be done with little effort as the overall power of the meta is greater than before, and a role that the metagame left behind was the "boosting/setup wall" because the games are now faster paced than, for example Gen 3, where CurseLax, CroCune or Amnesia Slowbro could withstand a heavy ammount of hits and stall/sweep the opposite team with the proper support. The setup wall role is per se risky in this meta, because a misclick, a bad switch in or a lack of boosts/field conditions turns it into dead weight, but with the rigth scenario it can solo most offensive playstyle teams and could slowly break opposite walls. On this sense not only direct stat boosts are required to succeed on this role, as passive damage (status cond., wheather, moves like Curse or Leech Seed, etc.), passive recovery (Ingrain, Aqua Ring, Type-Absorbing abilities) and disruptive moves can force the foe to work around this poke. The closer example of what I try to picture out is Storm Drain Cradily; it has decent defensive stats boosted by the SpDef sandstorm bonus (thus inmune to it's passive damage), it has an inmmunity to a strong and common offensive type (Water), but has glaring weakneses to Figthing, Bug and Ice types. With access to Stockpile and Ingrain it can survive a nice amount of turns with the proper setup, but it's poor offensive power and coverage coupled with it's unability to protect itself from stauts like Psn or Brn shuts down it's utility, so a misplay (and the fact it isn't bulky enough without boosts) is a great disadvantage to it's trainer, and that can be worsened if it was the only Water resist on it's team. As this concept is not restricted to the scenario/conditions set on the last paragraph it can be shaped with some other interesting variations, and maybe we could learn something interesting if CAP 4 were a viable setup wall/stall poke. Greetings and good luck with the project.