Well, Dante only inspected the world but did not enter right away. In truth, while he did consider the 'external' help type of power system, beast mastering or beast taming had different iterations.
There was the rank system of beast taming, where beasts were separated into stages and broke through each major stage in a similar manner to Eastern Fantasy martial arts or cultivation. Beasts of this system usually were Asian or oriental in nature and they possessed attributes.
Naturally, Dante least considered this system for his use because they were the most useless to him. Beasts of this system typically required a lot of time and work to manage, and although they sometimes fed power back to the beast master, it wasn't much.
Besides, elemental beasts were the most useless since Dante could cast any spell of any element himself, why would he need a beast to do it for him?