The human excitedly awaited the merman's response, mainly because Shiro was beginning to hint at just how painful his life under the sea turned out to be. He watched carefully as he drew the other creature, who Keith already began to despise with all his being, and his eyes trailed over the muscles he had that Shiro still lacked despite being so huge beside him. The raven-haired man watched this deadly merman with a scowl, before his expression dropped to a more gentle path when he looked back up at the friendly merman beside him, and up to the moon. So that's why he hated the night. It brought him pain, sadness, anxiety, paranoia. He had to constantly look over his shoulder, and Keith would never forget how fast the merman swam away the first time. 

He felt such an overwhelming ache that his hands fell angrily on the shark-like creature, wiping him off the sand and not leaving a single trace. He wished he could do that. Get down under the sea himself and tear him apart, with somehow god-like strength. It was just a fantasy, a spur of the moment kind of anger. He huffed, crossing his arms and looking seriously pissed. He wasn't even pretending or exaggerating, he was truly absolutely angry. He didn't want anything to hurt Shiro anymore, and he tended to be fiercely protective over those he cared about. 

But unfortunately. He lacked a tail and the ability to breathe under water. All he could really do was seethe from the shore, and hope Shiro would be alright. Gently, he took Shiro's hands in his own, initial fear dissipating away completely and replaced by trust. He gave his hands a small squeeze, a silent plea for him to be careful, that he hoped to see him again when that time came. To further address his will to protect Shiro as much as he could, he backed away and drew himself then Shiro injured. As much as he could with sand, he attempted to put bandages on the wounds that almost looked similar to the real bandage Shiro had on his shoulder now. He looked up at him, attempting a soft smile. But Keith knew the relaxation he felt from before was far gone. 

Now there was worry. Fear. Of losing his only friend.