Rivin, Flamesong Duelist

Rivin, Flamesong Duelist gets +1/+1 for each
color among other legendary permanents
you control.
{w}{u}{b}{r}{g}: Search your library for a legendary permanent card with converted mana cost
less than Rivin's power, put that card onto
the battlefield, then shuffle your library.
(Stand-in for Sisay, Weatherlight Captain)