The image shows that Bill Nye apparently is the voice for the announcer and Master Hand in Brawl, haha.
Yep, I like using DACUS on a shield because if the hitbox from the dash attack connects, it gives the mortar hitbox a higher chance of poking and connecting as well. Very useful for rushing an MK after nado like you said.
Although, it bugs me that Snake doesn't seem to have any reliable options for guarding himself from below when you've been launched vertically. He has bad aerial control, so mixing up your landing spot isn't possible. If I try to FFDair so that only the stronger, final hit connects, I can get it shielded then punished. And C4 is fail. I don't know what to do in those situations.