[BONUS]
White Unicorns valued their commanders and core members very much — that was for sure.
But Ren still wondered what was so special about Serine that she got a Dragon Birdbeak, which cost an astronomical sum of money. It was probably acquired through an auction, so other guilds probably coveted it for themselves too.
It might be part of her contract. Ren shrugged the matter off and concentrated on the matters at hand.
The Thunder King summoned [Hurricane Winds], making every mount that came near it get hurled away. All flying mounts had a difficult time weathering the storm, so most were flung away, including Serine.
Even so, White Unicorns didn't stop attacking. And since the Thunder King's arms and legs were already incapacitated, the head and body were only left with weathering spells and [Voice of Thunder] as a primary source of attack.