In terms of 2 individual champs, Kalista + Yuumi is really bad.
In terms of overall, It would probably be a team of 5 champions who function really well when given a condition, but nobody on the team can force that condition. Creating a team that has a very clear win condition but a complete inability to get that win condition would probably suck.
Maybe something like Samira + Yasuo + Sona + Low CC jungle + Low CC squishy top would do the trick. You would be almost entirely reliant of yasuo to land a tornado in order to actually win a fight, but otherwise you literally cannot engage. The sona pick would also stagnate Samira's ability to snowball due to a weak laning phase, basically leaving her even more useless than she already would be. maybe Yasuo can 1v9 that game, but I don't think it would be a good comp.
Edit: Another example would be a full Magic DPS comp. Ryze top, Karthus Jungle, Azir Mid, Cassiopeia botlane, and probably a support like lulu who l...