You could also just cast Finale for X = a lot
Opening Hand 6 Even without a land, this hand has plenty of mana, and is probably a reticent keep
Bristlepack Sentry Builder's Talent Crystal Barricade Demon Wall Fire Navy Trebuchet Fog Bank Gleaming Barrier Hide in Mundanity Hydraulic Helper Invisible Woman, Sue Storm Jaded Analyst Krotiq Nestguard Mechan Shieldmate Monoist Sentry Pit Automaton Platypus-Bear Redrock Sentinel Rouse the Swarm Rune-Sealed Wall Sanctuary Wall Shipwreck Sentry Sparring Dummy Spider-Man No More Stalked Researcher Super-Skrull Temur Devotee Territorial Witchstalker The Pride of Hull Clade The Walls of Ba Sing Se Ticket Tortoise Unruly Catapult Wall Crawl
However, if you do and the target is illegal as the ability tries to resolve, it won't resolve and none of its effects will happen
If you have one of the cheaper versions of Mega Lucario ex, its better to keep this one safe in your binder rather than put in your deck
Ghostly Prison is a three-drop enchantment that demands a mana payment of 2 for each creature attacking Ghostly Prison's controller