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Just tell me if there's something you don't like about her, both concept and numbers.
Some background regarding Cordana, the Shadow Stalker:
Cordana is good at both Long Range and Short Range. Distance isn't a problem with her, even though she is a Melee Hero. And since she is an assassin, losing sight of her target isn't an option.
She focuses more on a single target rather than the whole team, and killing her target as fast as possible. (An Assassin thing)
She is rather squishy and could have some mana issues due to having all 4 of her skills being active (Though one is both Active & Passive, you'll see.) but even though, her potential as a killer can't be underestimated.