Sayori, Bittersweet Life

As long as Sayori, Bittersweet Life is on the battlefield, creatures you control get +1/+1.
When Sayori, Bittersweet Life goes to the graveyard, creatures opponents control get a -1/-1 counter.
This creature can be cast from exile.
{1}{t}-Exile this creature; You may move any
counters on creatures to any other creature.
"Sometimes when you have a little raincloud in your
head... A sad poem can help give the raincloud a little
hug."