A movie is usually made up of several acts, so you could have a mode of play that represents several acts of a movie:

1 Player builds a deck that has 20 x (No. of other Players) + 10 cards, with as many duplications as there are players and as many sets of characters as there are players. So with yourself and 3 other players you would build a 20x3+10 (70 card deck), with no more than 3 copies of any card and take 3 sets of characters.

Now play through the acts:

Act 1: Players vs 4 Stormtroopers

Act 2: Players vs Dukoo and Grievious

Act 3: Players vs Kylo Ren and Phasma

At the start of each act players roll for initiative, and may return 5 cards from their discard pile to their deck, returning their cards in their hands and shuffling after. Drawing a new 5 cards.

It may take a bit of play testing to get the balance, but I'll trow it out for a concept.

I like that idea

There was an old CCG called Warlord: Saga of the Storm (one of my favorite ccgs of all time), and they did something that is alittle similar to this that I think could work well in destiny. Warlord had one character that was the leader of the deck. They had what they called Overlord and Medusian Lord decks which were super powerful with very powerful deck leaders and had things that broke the normal deckbuilding rules. They would send out the overlord decks to their local TOs and you would play against the deck and try to beat it. If you did you won the deck and could use it to challenge one of the Medusian lord decks that was one of a kind that the designers and employees of AEG would have. If you beat the Medusian Lord deck you won that deck and officially killed the Medusian lord in the storyline.

It was a really fun and challenging mode of play that took some of the focus off of pure tournament play.