Perdition Imperial Dragon, Dragonic Overlord the Great LR MBT01/L03

[ACT](VC): Legion 20000 "Perdition Dragon, Dragonic Neoflame" (If your opponent has a grade 3 or greater vanguard, only once, this unit may return four cards from your drop zone to your deck, and search your deck for the specified card, and perform Legion.)
[AUTO](VC):[Counter Blast (1) & Choose two cards from your hand, and discard them] At the end of the battle that this unit attacked a rear-guard, if this unit is in Legion, you may pay the cost. If you do, [Stand] all of your vanguard. This ability cannot be used for the rest of that turn. (Even if you do not pay the cost, this ability cannot be used for the rest of that turn.)
[AUTO](VC):[Choose one of your rear-guards with the same name as a unit in your (VC), and retire it] When this unit's attack hits, you may pay the cost. If you do, choose one of your opponent's rear-guards, and retire it.