Exusiai never goes niche. She's the best ranger and most of the best players recommend you build up at least 2 rangers.
A lot of rangers go niche mostly because they no longer have enough attack to do more than the minimum floor damage. But Exusiai has the advantage of being a 6* as well as having high damage mods on her skill as well as her random buff, which would suck if it went to HP%.
So yeah you should definitely get her one day. Maybe save up dem tickets
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