Beast Taming: Building the Strongest Beast-Taming Corps

[Beast Taming + Leveling Up + Fusion + Evolution + Invincible] Reborn in another world, where beast taming is the mainstream. He awakened a god-tier talent: fusion. Are your beasts too weak? Would fusing them into a giant serpent be enough? If not, would a flood dragon be enough? Still not enough? Surely an Azure Dragon would do? Is your beast-taming space too small to hold them? Would one fusion be enough? If not, no problem. We can keep fusing them.