Yes, I recommend double sleeving especially if you play with valuable cards, transforming cards, or modal dual-face cards
This is unsurprising, as board-wiping with benefits is a powerful concept for a card
Since Shiranui Synchros effects range from changing battle positions to destroying cards on the field, to boosting attack points, they can hold their own in a wide range of scenarios
If youre not battling, opening 1 pack every 12 hours IMO isnt enough to suck the F2P or casual onto the app for a long time
The high mana cost on activation should mostly keep this away from creatureless control decks, but if I were running a white creature deck that could consider Glorious Anthem, this is a big upgrade from there
While discarding a significant portion off the opponent's deck is effective, keep in mind that the attack also discards the player's deck