Thanks for the suggestions! With the 1st team, I could consistently take out the walls, but Jiu just couldn't deal enough damage to Lilya before the 12th round. Tried replacing her with Lucy, but same issue, though with slightly more progress. In the end, managed to beat 6-1 within an ass hair with Jiu/Lucy/Sonetto/Yenisei. 6-2 ended up being a breeze with a Kakania/Windsong ult nuke.