[+1]: Up to one target nonland permanent gets -1/-1 and loses all abilities until your next turn.
[0]: Target creature you control gets +2/+2 and gains lifelink until your next turn.
[–1]: Each player discards a card. Then you may pay 2 life. If you do, draw a card.
[–3]: You and target opponent's life totals each become equal to half your combined life totals, rounded down.