The merged creature is the same creature it was before the merge, so any Auras or counters that were on it remain on it, it remains tapped if it was tapped, it's still attacking if it was attacking, and so on
DP: My work is so line-centric that rather than painterly shapes that scale down for print easier, I had a real worry the lines would mush together and become unreadable with too much reduction down to card size
Prosper, Tome-Bound again, obviously
The lethally-cute combination of Regal Bunnicorn and Mockingbird can lead to surprise wins through the air, while Steel Seraph is at its best surrounded by larger individual bodies
There are situations where you are in a great disadvantage or in a dire position and you need something massive to stay alive and come back to the game
It also lets all lands enter the battlefield untapped, which is really nice and makes this a fantastic inclusion for a lot of decks with budget mana bases