When Sutina enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Whenever Sutina attacks, you may return a land you control to its owner's hand. When you do, put a +1/+1 counter on target creature.
You don't choose a target for Sutina's last ability at the time it triggers. Rather, a second "reflexive" ability triggers when you return a land you control to its owner's hand this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.