Destiny, one of the biggest new IPs in the recent few years.
Dynasty Warriors one of the largest franchises in Japan, and a franchise well known for crossovers.

Imagine for a moment, you are Bungie (or if Destiny 2 slips, Activision Blizzard) you know your big budget IP does not have a overwhelming appeal to the large Japanese market.
What do you do to remedy this dilemma; Fund Destiny Warriors, that's what!

Personally, I do not care about Destiny nor do I play musou games very often;
but I believe that seeing a Destiny Warriors reveal trailer would be worth $60 USD from me.

What features would the game look like?
Will this game sell in Japan, or anywhere?
Would you buy a Destiny Warriors?

No. Please no. The game would be awful.

Yeah, but that would be the best part.
Like a garbage movie, a movie so bad that you cannot help but laugh.
This game would likely create more value for people who do not play it.

Oh god Destiny Warriors.... that would be strange with only three characters.

I thought they only collaborate with Japanese games?
and NOPE! There are other games that are much better to do it with:
- Pokemon
- Super Smash

._.

You kind of need, well...y'know, swords to make a Dynasty Warriors game work. Why do you think LoZ and Fire emblem were chosen?

In terms of creating a good game, yes go with Pokemon or Smash.
If you want to make people smile, even the people who will not play the game...
Destiny is your game to do a crossover with.

Does Destiny have melee, or will the guardians (?) have to punch their foes?

Destiny is a bad ripoff of Phantasy Star Online games. Destiny fell flat on it's face. They only make Warriors games of successful LIKED franchises. The audience that likes games like Destiny is not the same people who like Warriors as a general rule. You may as well say you want a CoD Warriors.

That is true! But zelda did have characters without swords, but I see what you mean.