Once you cast a spell using flashback, that spell will be exiled once it leaves the stack, whether it resolves, is countered, or tries to resolve but fails
Evolving Credits: After the group goes off to confront the Dark Signers, the intro sequence adds scenes of Jack and Akiza facing off against their opponents, as well as reanimating Leo and Luna simultaneously summoning their dragons, and replacing Yusei's Turret Warrior attacking one of Kalin's monsters with another of his monsters attacking Roman's Earthbound Immortal
Then, bring Shenshen back from the GY, and move in
How to Sell Your Trading Cards Selling your trading cards is quick and easy at Bitjump Games
These "symmetrical" artifacts impact the board equally, but Urza's ability to tap artifacts at instant speed gives you a way to break that symmetry to make sure that you will be the only player at the table actually casting spells