Ishtar

When Ishtar enters the battlefield
add +1/+1 counters to all your creatures.
Any Owl Bears get +2/+2 counters
{t}{g}{1} to give all your creatures +1/+1
until the end of their turn.
{t} Ishtar to sacrifice and add {r} to summon Euphoria, Prince of Music from your library
to the battlefield taped.