Response

@Strider92: I just rewatched that fight and no one helped him out. At the start of the fight the monster throws and axe at Leonidas while he wasn't looking so while he could've killed Leonidas then, it wouldn't have been through a real fight but a sneak attack. Then about midway through their fight, a Spartan tries to help but quickly get kicked away serving no real purpose. Leonidas uses the time, about 1 second, to draw his sword. If they had been having an official fight you would assume he would've had time to draw his sword at the start of the fight anyway so all this did imo was make the fight fair.

Would you not agree that this monster was at the very least as powerful as the Shadow of Death? He did after all effectively pwn 2 Spartan elite warriors in seconds and yet he was still defeated by Leonidas. As I've mentioned already the Shadow Of Death was by far the most powerful character in all of Spartacus and was only defeated due to Spartacus and Crixus using his weakness to sunlight against him. Even in a 2v1 he still put Crixus out of action for a long time and ended the career of Oenomaus.

My conclusion is this: Leonidas>ImmortalMonster=ShadowofDeath>Gannicus and I'm sure you can at least agree that the Shadow of Death > Gannicus.

In response to your second point, I agree.