Mei-Ling Zhou by Crackjack

Mei is a ranged warrior which is very effective against basic attack dominant heroes
on the other hand she will be very vulnerable to spell damage

Frozen Liquid - Gives a slight disadvantage to Mei as she has to stand still while using abilities and basic attack and she also has to keep moving to regen Frozen Liquid

Frost Shock - Offers a root and at the same time aoe slow to others hit by Frost Shock
It also gives a disadvantage to Mei since its a close range ability which of course requires Mei to be close to the targets

Cryo-Freeze - Offers a great Aoe attack speed slow, a great tanking ability and a great survivability to Mei
But on the other hand its vulnerable to spell damage and can be destroyed

Ice Wall - The ability gives a good shielding against enemy projectiles, vision blocking and stops heroes from escaping
This is also destrutable and can be a downside since it also blocks your own vision which can lead to unknown deaths :-)

Blizzard - Gives a great AOE control but can be avoided by enemies if a hero walks away from the area

Drone service - Increases Meis tanking ability and allows for lesser crowd controling