You can increase your odds of pulling a Rainbow Rare by buying as many packs, lots, and entire collections as possible
Strengths: Weaknesses: Upgrade path: Buy Red upgrade cards (Admiralty support, cost reducers)
Dualcaster Mage is the easier card to go infinite with, since it doesn't require being cast to copy spells like Ghostly Flicker, though the otters still great as just a body that doubles up on another spell you're casting
Debuting in Japan in 1999 and the rest of the world in 2002, the Yu-Gi-Oh
The downside is still a Goblin Electromancer that occasionally pings you for damage, but the upside is flipping this planeswalker into Ral, Leyline Prodigy, a fairly tame walker that preserves the front side's cost reduction and adds in some other forms of disruption