As long as it's on the battlefield, Shanna's last ability will count itself, so it'll be at least 1/1.
27-04-2018
wotc
Spells your opponents control can target Shanna.
27-04-2018
wotc
Shanna's ability that modifies its power and toughness applies only while it's on the battlefield. In all other zones, it's a 0/0 creature card.
27-04-2018
wotc
Because damage remains marked on a creature until it's removed as the turn ends, nonlethal damage dealt to Shanna may become lethal if other creatures you control leave the battlefield during that turn.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.