Yes and no. You can use P/T stickers as well, but for ticket value we look at the toughness of the creature, not its power, so you wouldn't be able to put it on the Sergeant.Can you use the P/T stickers to upgrade a card as well? E.g. there's an 8/4 P/T sticker that costs 4, can you make the Barging Sergeant an 8/4 this way?