onrik: get ready human, we're about to arrive
The battle was about to begin, so he had to be prepared for anything that might happen, especially if he had to fight several enemies at once. Also, the place where he is is very advantageous for flying creatures, since it's basically a large plain surrounded by large mountains.
Thanks to onrik's large size, they were seen immediately, but none of the wyverns present did anything other than look at them, and Kuro could perfectly see the difference in size between the other wyverns and onrik.