Ronragruk acceded immediately to let Shirk be the first in having the bloodline improvement once Yale told him.
Although Ronragruk knew that Shirk probably wouldn't remain in the tribe, he knew that it would be difficult to find someone so eager to be the first one given the danger that implied.
Moreover, since Shirk was Yale's friend, he already assumed that would also have his bloodline improved at some moment before Yale's group left, and Ronragruk already considered that as an unspoken payment for Yale's help.
The next day, the experiments about improving Shirk's bloodline started, but given the level of difficulty they just worked a bit on it each day as trying to rush was dangerous for Shirk even tough Yale could use Time Healing to avoid major problems in Shirk's body after failing.
