It is based on swarming the field through many different effects. Cards like Supreme Synqlu - Knight of Honor Special Summon 1 Level 4 or lower Supreme monster when Normal Summoned. This can set up for easy Synchro Summons with cards like Supreme Zexion - Thunder Jumper or Supreme Beast - Forest Cat.
Another easy way to swarm the field is with the use of Supreme Yale - Insect Samurai.
You can discard a card with the effect of Supreme Yale - Insect Samurai to Special Summon 1 Level 3 or lower Supreme Monster from your hand. This could lead to another Supreme Yale - Insect Samurai or Supreme Zexion - Thunder Jumper which can provide easy Synchro summoning.
There are also 3 good Spell and Trap Card support for the Supreme archetype, making them even more great. Supreme Decision is one of them. This card can help get an easy Supreme monster, but is a -3 on some occasions.
Supreme Eye is another support card. It requires you remove from play a Supreme monster you control, which can put Supreme Yale - Insect Samurai to great use. It can also help match-up the levels for a possible Synchro Summon.
The last of the support cards is Supreme Decloration, which in a sense is like Royal Oppression. You pay 2000 to activate it, and then only Supreme monsters can be Special Summoned. This card can also be splashed into decks that don't use Special Summons, like Spirits, making them even more deadly.