The problem with both Ash and Grim was that their talents weren't particularly high. Ash knew that in the grand scheme of things, that there were far more people with better innate abilities. Starting with stats for example, the young scions here most likely out did him.
The nurturing of a clan was something foreign to him but he understood the effect it had on a person. Better innate abilities, better martial arts, and even items that could increase things like memory or elemental affinity.
Grim's spirit talent was good but not nearly enough to alleviate his bubbling worries. When it came to monsters, rank was more than a barrier you could pass through leveling up with just experience. It would depend on a combination of: bloodline, nurturing, experience, and comprehension.
Grim started off as an f rank monster, however the limits of his stats were more important than the rank itself. Bloodline and comprehensive ability reared their ugly heads in this area. The watchling from before showed hints of evolving into a beast with a better bloodline. Those who had a better bloodline started off at higher ranks, had higher capacities for that rank, and it was easier to rank up.
The watchling for example may have an agility cap of 40 for e rank, while Grim might have a capacity of 28 IF he could level up to e rank in the first place. This indicated that the watchling could even fight Grim if Grim was a higher rank. With a lower bloodline, Grim's stats would put him at a disadvantage against opponents with superior bloodlines.
They were both children and that would speed up growth in stats, but it was more likely the watchling would go onto another rank before Ash could even make it to that rank. The ranking up of a beast was easier if they had the innate talent to move onto the next rank. Grim could potentially be stuck at his current rank for longer compared to the watchling.
Comprehension was the gateway to skills and the production of not only higher stats, and efficiency, but also increased options for evolution.
Ash was visibly starting to get down at this point. Grim hopped in front of him and cawed at him. He looked Ash in the eyes and through their bond gave off the emotion of determination. The wave of emotion was strong enough to jolt Ash as he came out of his deep thoughts.
Instead of crying about how hard life was. He decided to make a plan to destroy the dead end pathway that lied before him. Fate needed to be grasped by his hands and Ash refused to let it determine his life. If this bird in front of him wasn't moping around then neither was he.
The bond between the two at this moment got a little bit thicker than before.