Jeskai players have been waiting for this card for a long time. It basically preserves all your Dive Down spells, and can be even used to a great effect with Thrash.
Another great choice for this card would be Essence Capture, a counterspell that also puts +1/+1 counter on your creature, which is especially relevant in the War of the Spark meta.
It'll keep you supplied with counterspells until Feather, the Redeemed stays on board, and will help you grow it bigger as time passes by.
But this doesn't mean that it can't be used in straight-up Boros Aggro decks. On the contrary, you will see it more often than you would expect.