Some pokemon get new move or new ability, then be too strong and have to up to higher tier.
For example:
1.move
Blastoise's Shell Smash
2.ability
Feraligatr's Sheer Force, Serperior's Contrary
I wonder that if add a new function to ban pokemon's specific combination, would it make a pokemon could be use in different tier at same time.
like OU's Dugtrio, if ban its Arena Trap then will drop to NU.
Torkoal if ban its Drought might drop to Untiered. XD
After all, a best usage causes a pokemon to use in high tier only, is too waste its others usage.