She's REALLY good, and if you can keep her on the board, she can quite quickly murder even high level monsters. Shame that PvP will always find a way to punch her down one way or another. She can also work well with Armor Exe since one way or another, you'll wind up getting at your opponent's life points, be it using Armor to destroy Gross Ghosts or using Maiden to cut through everything else and keeping Exe on the board by sacrificing her spell counters that she'll accrue each turn.
Which is a shame that it is rated so. One of the few Spell Counter cards that doesn't get Counters from Spells and can power over most lv 4s with just 1 SC. I admit to using it less when Crusader/Endiyum (however you spell) came around, but still an excellent Spellcaster.