Shackle's targeting is decided when WR fires it, not when it hits you. This can make things a bit weird at times.
She's just a lot of fun to play. Incredibly versatile, her skills are fairly low CD/mana, and Shackle/Powershot are both really satisfying to land. Plus once you get get Force Staff / Phase you get to laugh at people that think they can kill you.
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No amount of planning will ever replace dumb luck.