It looks like a Ninja Gaiden Trilogy is coming to PS4 and Nintendo Switch. The Trilogy looks to include Ninja Gaiden Sigma, Ninja Gaiden Sigma 2, and Ninja Gaiden 3: Razor’s Edge. The listing was found on Game Source Entertainment, which is a large Hong Kong video game distributor. If the listing is to be believed, the collection will come out in March 2021. With TGS just a few weeks away, it's possible that we'll see a reveal there.