If I use Litwick's "Brighten and Burn" attack and choose to not discard that card, what do I do with it?
You put it back on top of your deck if you don't discard it.
Source: Black Bolt/White Flare FAQ; TPCi Rules Team (2025-07-17)

Relevant cards

Note: All applicable cards may not be listed below.
RSV10.5_16
RSV10.5_16