Sonic, the Hedgehog

Whenever an Aura you control enters, if you
cast it, you may search your library for an
Aura card with mana value less than or equal
to that Aura and with a different name than
each Aura you control, put that card onto the battlefield attached to Sonic, the Hedgehog
then shuffle.
"Gotta go fast!"- Sonic, the Hedgehog