Revealed last night during the official Twitch E3 stream, Studio Saizensen's Blade Strangers is a 2D fighter that combines the speed of Guilty Gear with the easy inputs of Smash Bros. More importantly, it let's Curly from Cave Story fight Solange from Code of Princess.
Studio Saizensen is the development studio behind 3DS action RPG Code of Princess and the most recent game in the bizarre Umihara Kawase series of fishing platformers. Publisher Nicalis is known for working with indie developers on games like Cave Story. In Blade Strangers, in development for the PlayStation 4, PC, Switch and Japanese arcades, characters from both companies' portfolios clash on battlefields inspired by their respective games.
Studio Saizensen creates its fighters as 3D models for purposes of animating, then converts those animations into 2D sprites, which sounds like it's a lot quicker than hand-animating every frame. It sounds similar to what Arc System Works has done with the most recent Guilty Gear games.
The folks at Nintendo Everything captured the full Blade Strangers segment from the Twitch stream for your viewing pleasure.