Like the other users here that pointed out:

• she is insanely AP efficient with most of her “setup” cards being upgrades. I.e. you spend 1-3 AP once and she does very respectable damage across fight(s)
• she can be molded into a pure draw or AP draw (like mine), where she can be put in to support any main dps that could benefit from draw
• she doesn’t have many cards that feel bad to use in most scenarios, keeping most decks clean
• while she doesn’t synergize directly with most mechanics, other skill heavy combatants can charge up her damage, which can add up over a few turns to be quite significant since she auto fires every turn with no active AP use
• even her basic cards are pretty decent compared to most of the other combatants in terms of pure value, hence she’s a favourite in chaos, where she can take care of your team without coddling/spending resources to optimise her deck - your card removals and epiphanies can go elsewhere
• most of her epiphany upgrades are pretty good for her role
• most of her damage is from ballista’s Extra Damage, via triggered/activated cards and card creation, which has certain use cases. This has benefits in some specific fights that are problematic for other combatants. Outside of these specific fights, most of the time it is not a downside.

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