so i have been thinking about this for a while and i think that i have finally locked down how it might work, its a little easier now to make it happen when i actually own the 5E PHB as opposed to trying to figure out how to make it work as a wizard i can actually make it work as a sorcerer and it will make a little bit more sense.
so the basic idea behind this is that you are playing a summoner of some kind, and that you are using any magic deck that you have to do said summoning. you use lands and stuff as normal to gain mana and then you cast anything that you want from the deck using the normal rules of magic to cast said card. the creatures that you summon work much like any creature that you would summon in a game of magic, much the same as sorceries, equipment, and auras. there are some caveats upon this, and they will be listed below and within the class outline itself.
Metamaigc - a change here is that instead of taking one of the different metamagic options listed, you can choose to use the following option:
Different Colour -
when you choose this option you can add a different colour to your Magic deck. this option can be taken more than once.
Your innate magical prowess comes from the ability to summon a variety of different creatures, beings, and artifacts from the different planes of existence. this ability might have been granted to you from a pact with a creature of higher or lower powers, or something that was passed down to you from your parents, or maybe you were yourself summoned once and it changed you.
when you chose this origin, you can put together a magic deck using the normal rules for deck creation, this can only be one colour though.
by choosing this origin you lose the ability to cast any spell outside of cantrips, that isnt from your magic deck
you can use your sorcery points to cast spells as though they were mana of any chosen colour, you can also use your spell slots to turn them into sorcery points.
at 6th level you gain the ability to summon a creature that you can keep around for an extended period of time (a number of days equal to your level), if you do this it is restricted to the rules that are used when selecting a commander for the format of the same name (commander or elder high dragon)
at the beginning of every day you draw your hand, and can use these cards whenever.
when in combat you roll your initiative like everyone else, but you can do the following action
Play Magic - full action
you go through a turn of magic
when you enter your attack phase, you creatures hit (without a roll needed to hit), but they only do their attack points of damage.
as a reaction you can use your cards to block, this option must be chosen before any roll to hit is made, because regardless of the outcome of any roll, if you chose to block they will automatically hit.
you can also cast an instant whenever you would legally be able to
so this is about as much as i have at the moment, i cant quite think of how to use counter spells and the like, but when i do i will add to this for it.