THE STORY IS: Following the first and second season, Keima has released 14 girls from the grasp of runaway loose souls, but a new problem has arisen. Diana, a goddess who possesses Keima's neighbor Tenri, tasks Keima with finding and awakening the other Jupiter Sisters. The only clue he has to go off of is that any of his previous conquests could be targets harbouring goddesses inside of them, but only the ones that retain any memories of the conquest. Keima must now hunt down each of his past conquests in hopes of finding which ones harbour a goddess inside of them and draw them out by having them fall for him again. Time is now a factor as an organization from Hell called "Vintage" is aiming to kill the goddesses to awaken an ancient demon to take over Earth. Now Keima must win these previously conquered hearts a second time to draw out the goddess that lies within them before Vintage gets to them first.
The story in The Goddess Arc is, by far, much better than it's predecessors. Unlike the first and second seasons, this arc had a sense of urgency behind it and it worked with the overall theme. Something bad was happening and the clock was running out. Conquering the girls this time around was a bit more of a task which added to the sense of urgency throughout. Sure, it was a bit cliche, but anymore an original idea is hard-pressed to be found anywhere. Find these girls before an evil group does who is up to no good. The way everything played out was much better than expected. I had little hopes for the Goddess Arc because of how I felt about the first 2 seasons. It blew my expectations away. The story is still the same, even though it took a step back in a sense and added pressure to the overall events. More like a life or death situation. Definitely a story that got way better over the course of time.
THE SOUND & ANIMATION: Watch the first 2 seasons and you should expect the same here. Voices are well done and animation is great. Elsie's voice is still annoying though.
THE CHARACTERS: This department ramped up a lot in this arc. All the characters were a little more explored which got you to know them a bit better. Some characters from previous seasons make another appearance in some way. The development was much better this time around. Keima made the most improvement out of everyone. He starts to seem like a normal person with feelings and an attempt at the real world without being glued to video games. All the other characters made tremendous leaps forward and brought forth some real development. Everything between the characters flowed without skipping a beat.
OVERALL: Goddess Arc is definitely worth watching by far. I did not particularly care at all for the initial series itself, but this arc brought me to love it. Definitely a story that got loads better over time. If they were to come out with another arc or season, I would be all for watching it as long as it was anything similar to Goddess Arc. I would say to watch the series to get to this story arc. Worth it.