She already exists in a lot of white weenie lists throughout most of Magic's many formats, including countless cubes where white aggro is a playable archetype
And they are way, way better than anything you can print out yourself
Rikku also comes with an activated ability that lets you Steal opposing counters, and her ability to make a creature that gains a counter unblockable for a turn works very nicely alongside Tiduss proliferate trigger
Baloo, Von Bruinwald XIII has the Bodyguard keyword which means that whenever an enemy character challenges one of the players characters, they have to target this card instead
White also doesnt tend to get much in the way of mana acceleration, so this is a nice bonus for decks to try
During the Odyssey block, I just put a lot of squirrels in