Lagrella, the Magpie

When Lagrella enters, exile any number of other target creatures controlled by different players until Lagrella leaves the battlefield. When an exiled card enters under your control this way, put two +1/+1 counters on it.

Streets of New Capenna

When Lagrella, the Magpie enters the battlefield, exile any number of other target creatures controlled by different players until Lagrella leaves the battlefield. When an exiled card enters the battlefield under your control this way, put two +1/+1 counters on it.

"This way" refers to cards entering the battlefield as a result of Lagrella leaving the battlefield.

The last part of Lagrella's ability is a delayed triggered ability that is set up as its enters-the-battlefield ability resolves. It will trigger when Lagrella leaves the battlefield even if it's somehow lost its abilities or become a copy of something else.