Security Upgrader

[ACT](RC):If you have a grade 3 or greater vanguard with "Seraph" in its card name, and you did not ride this turn, [COST][retire this unit], search your deck, hand, or drop for up to one grade 4 unit card with "Seraph" in its card name, ride it as [Stand], and if you searched the deck, shuffle the deck. If you rode the card, your opponent chooses a card from their drop, imprisons it in your prison, and the cost of the original [AUTO] ability of that ridden unit decreases by [Counter-Blast 1] until end of turn.