Watch the Promo for the Season Finale of Supergirl

The promo for the Season 3 finale of Supergirl has been released. The episode is called, “Battles Lost and Won” and it will air next Monday, June 18.

In the episode, “Supergirl (Melissa Benoist) and team take on Serena in an epic battle for Earth.” Fingers crossed they defeat her without any casualties.

What did everyone think of tonight’s episode?

Source: CW