It's like how trample works on a creature: excess damage is dealt to the creature's controller
deck by discarding Spell or Trap cards like Danger
Shadow is one of the main mechanics from the Tempest block which is comprised of Tempest , Stronghold , and Exodus
Cyber Dragon Duel Terminal Preview, Duel Terminal Rare/Parallel Rare ($1,730) Arcade machines such as beetle-battling Mushiking (which was initially released in 2003), as well as its many sequels and spin-offs, as well as more recent fare such as DC superhero-based fighting game Injustice and even Minecraft Dungeons Arcade, dispense trading cards with every credit
As for copying spells, it allows you to copy any artifact spell by just paying 1 extra mana, which is sick, but you have to be aggressive to build up to max speed