The barrier over the ring likely cancels out Sakuya's time-stopping. Indeed, I think that's what nearly got her blasted (and what DID injure Koakuma) when the Hellraven surprise-attacked everyone.
Also, the only reason that Satori started backing Orin up in the first round is because Ran was backing up Chen. Before that, Satori let Orin fight on her own. Satori also warned Orin about Sakuya's sneak-attack, which wasn't strictly within the rules since neither of them were tagged in.
Satori's not out to break the rules except in extenuating circumstances.
Going by "I love the sea" and "kyuuin" I think the background noise is most likely the kappas singing while they work.
*gan-gan*If you are going to do it, seize it with your own strength.*I love the sea~!*Thank you...Huhu...Really.*to-da-da!**It's a big deal! A big deal!**ga-ga-ga-ga!**Achooooo~!!**huff huff*Oh well, I have achieved half of my objective.
The one who threatens, the one who takes*gan-gan**kyuiin*It'll be bad to let Yuugi keep her full stamina.This is so obvious.Episode 495: Aces* Sealed* - "Main cannon" in japanese
From the Artist's Pixiv page...Okay....for having trust in Orin.Even though I have listened to the girl's* plea...
* Koakuma...Whether that will be realized or not is up to you.