My idea for a Bandana Dee trailer:
Done in Triple Deluxe cutscene style.
at Queen Sectonia's castle, Kirby is fighting Dedede (Taranza Controlled?) when Kirby gets the upper hand Dedede transforms into Masked Dedede (revealing new final smash) and easily overpowers Kirby. When all hope seems lost and Kirby is about to lose we see a black shadow swoop in and defend Kirby from Masked Dedede, Kirby looks up to see that this character is Meta-Knight (confirming his return) we then cut between gameplay of Smash with these 3 fighting in the new Queen Sectonia's Castle stage and more of the cutscene. the trailer ends with Sword Kirby and Meta-knight about to finish Dedede off.
the screen goes black, you think it's over and then there's a faint noise it slowly gets louder, you realise it's footsteps (Kirby series footstep running sound) Bandana Dee runs onto the black screen and trips over in the middle faceplanting. Kirby runs on screen and helps him up and then BAM "BANDANA DEE WADDLES INTO BATTLE" we then get gameplay footage of Bandana Dee fighting various characters, including a scene with all four Kirby reps similar to the Robin/Lucina trailer. and the trailer now actually ends with Kirby and Bandana Dee doing the Kirby dance together.
It's just an idea, and I'd rather see Dee do something awesome and be the star of his trailer, but somehow the idea of him practically being late to his own reveal and faceplanting and stuff is just too adorable x3