Abel learned something by being with Black Wind and White Cloud for so long. If you commit yourself to bonding with your mounts, they would most likely do the same to you. And not just that. On a practical level, Abel's the one who's been sharing the soul potions with Black Wind and White Cloud this entire time. He was literally their go-to for boosting their intelligence and strength.
By calling with his soul chain, Abel told White Cloud to make a landing beside the two clawed dragon. The dragon was nervous to see a sky sparrow this big, Abel kept on telling it to calm down. Eventually, it started seeing White Cloud as its friend, as a fellow member of the same team.
It's good to see that a two clawed dragon would befriend a creature that's not the same species as itself. Because of how quickly it assimilated into the team, Abel decided to give it a soul potion as its reward.
