>>45995696I went ahead and took on the E4 without a 6th member, and with Vileplume massively under-levelled. It was a success!
I got through the actual E4 without any losses. Skipper the Swampert oneshot every member of Lance's team with Ice Beam. Faith the Gyarados set up with DD and one-shot every member of Glacia's team after Humphrey the Camerupt took out the first Glalie. Syndey went down to a combination of Humphrey for his Grass types and Faith for his remaining Pokemon. Phoebe was the toughest E4 member, but still not much of a challenge - Crowley the Dusclops took out her opening Dusclops and Banette pretty easily, and then Skipper and Humphrey took out the rest of her team.
Steven was a little tougher than expected. Humphrey oneshot his Skarmory, but I misplayed against Metagross and used EQ instead of Overheat so he sadly died then, with Skipper avenging him. Crowley took down Cradily and Armaldo with status conditions and Rest, and then Aggron was oneshot by Skipper. Sad that I lost two team members, and Faith the Gyarados could do very little because of how bad her movepool was, but still satisfied to win my first Nuzlocke - and without using items in battle too.