User blog comment:SayuriDarling/Full first chapter of The Mark of Athena/@comment-24.208.158.68-20120607204315/@comment-3146930-20120607210745

In Polyphemus' defense, he woke up before Hera had all her power drained. Because of this, he wasn't at full strength and even claimed he was at his weakest as he had just woken up. With Hera free, there was a god and about 4 demigods ready to kill him. He made the right move in running away.

Enceladus was the first active giant to really do anything during the series (Alcyoneus doesn't count). Olympus was closed so obviously a god wouldn't come to their aid to kill him. He is also the physically weakest of the giants and relied on his inability to die to kill Jason and Leo. If you can't die, then who really needs a plan B?

Alcyoneus obviously has the best defense. He can't die as long as he stays in his territory (Alaska), even if a god and demigod work together. However, that doesn't mean he can't be trapped or knocked out. I mean if they had tied him up for example, he would still be alive, just unable to move. Also, Arion was with them and he is the child of two gods. Or Alcyoneus is only immortal in his own territory and can be killed outside of it like a monster.

Lastly, Percy was more sick from seeing evil Centaurs and Cyclopes and was having more of a mental break down at the time, allowing Polybotes' abilities to effect him more. When they fought again, Percy was ready to go and had a clear head. All he needed was a god to land the finishing blow.

If you notice one thing about all the Gigantes so far, they are all very arrogant, possibly a family trait. They believe that this time around, they have a perfect plan to defeat the gods and with all the gods ordered to stay on Olympus, there really isn't anyone to oppose them. However, Polyphemus hasn't been heard from since his defeat in The Lost Hero, so you have to wonder what exactly he is up to