Okay, so if you have played the new Nemesis Draft mode, you know that it is a cluster**** of arguments and disagreements. Here are my questions:
1. Who do you think should be banned?
2. Who do you think should be picked for the opposite team?
1. You should ban the champions that you don't want to use. Usually,I ban Singed. Sometimes they will give you champions like Zilean and Janna,people think that they are bad choices,but they can carry the game if played correctly.
2. Read Meiyjhe's answer.
Thing with nemesis mode is that you should pick based on comps, not based on champs. I mean there are some champs that are really bad on their own (Urgot), but really you want to focus on giving the enemy a composition that just doesn't work. This can be a full ADC comp, a full tanky-no-damage comp or something along these lines. This way the enemy team doesn't stand a chance, even when one of the enemies happens to main one of your picks.
2. Read Meiyjhe's answer.