Keen Duelist is a decent generic card advantage engine, but youd be better off with something like Lord Skitters Blessing for the additional enchantment synergy
If you are playing a board game or something, and you are really competitive about it and no one else at the table is, its not really fun for anybody
But she has no evasion, so ideally you'll be adding in white flying, protection from creature Auras and red haste, and equipment like the Swords of X and Y to pump her power and then not be blocked, and give you four triggers too
Only hitting instants and sorceries is a little restrictive, but this is still one of the best counterspells in the game
This deck will quickly build a powerful board presence, generate tons of value, and is very difficult to interact with