You want a bunch of cards that synergize with treasures, like Goldspan Dragon, Academy Manufacturer, or Reckless Fireweaver
Well, BanefireBanefire and Crackle with PowerCrackle with Power are obvious, game-ending threats, but we're also sinking that mana into draw spells like Blue Sun's ZenithBlue Sun's Zenith, too
Magic: The Gathering has seen a lot of changes lately, with some of its formats getting either direct interventions from Wizards of the Coast with bans, or massive shakeups with new releases
They have even hosted some PTQs
For border extensions, you can make a little O of tape and stick one side to the work surface and the other to the back of the card
Nowadays, most people would quickly look to either Pokemon or Yu-Gi-Oh