This is the tierlist for the average ranked player, so don't you dare to say Maeve is SS because some PWC player can make it work. Your average ranked player will not.
Forbidden ones: they are OP even if you are bad.
Strong ones: work even if you're bad, but if you are good, they are OP.
Situational ones: may be really good if you're good and pick them in the right times, a disaster if you pick them in the wrong times and don't have enough skill.
Maybe troll pick: if someone pick that on your team, you know you will have to do your work, and half of their work.
Troll pick for sure: you lost.