This episode was full of vital information and setups, in this review, a lot will be covered. Season 4 is off to a recap from Hestia. She starts off talking about Bell's honest desire to be a hero. Bell can be naively honest which leaves him susceptible to being taken advantage of however I believe to point of Hestia's recall is to highlight why and how Bell was able to become so strong for us the audience to see shifts in his motivation to become stronger in the future. You don't always notice what you didn't know was there.
Bell To Surpass Ains
Liaris Freese Bell's growth skill is a direct response to his honest desire to get stronger. The bravest thing to do is to act honestly in a non-naive way. Hestia makes it clear that because Bell Fought the Battle of Knossos to protect the Xenos, ( Probably the fight with Dix) he could generally be considered worthy of a rank-up.
Hestia narrates that the fight with the Black Bull Asterius was the final push for Bell's status to level up the frustration that she felt.
Hestia's narration can be interpreted in two ways, Asterius is a beast literally, he took on Ains one-handed, any level 3 just fighting him and losing is enough for a rank up. Or is Bell's rank up connected to Bell's feeling the way that Liaris Freeze is based on his desire to get stronger does it help him level up.
If so is it possible for Bell and only Bell to level up more than one level at a time if he wants it bad enough?
We know that the Black dragon that defeated Zeus Familia's level 8 and Hera Familia's level 9 is in the future so maybe a double rank up and level boost will allow Bell to close the gap.
Anyway, the point of recalling Bell's past motives and frustration at his loss is to show his motive moving forward, he's never going to want to lose to Asterius again so he has to get stronger.
Hestia saying vesta seemingly out of nowhere and then explaining that it's another name for herself and title meaning perpetual flame seems very symbolic and open to interpretation again.
Is Hestia relating the word to Bell and his perpetual desire to get stronger or is it more about Hestia herself?
After saying what the name Vesta means we are shown again the symbol of the Hestia Familia symbol a flame burning over a bell. Perhaps Hestia felt like saying it because she wants to watch over Bell forever after recounting their journey so far?
Fells Gives Bell A Goal And A Warning
Fells lets us know that injuries don't always heal cleanly by stating that he/she takes it that Bell's injuries have healed cleanly. This may be vital information if wounds don't always heal cleanly it may be foreshadowing a situation where healing potions may do in the dungeon may do more harm than good. We are told later in the episode that Naza is working specifically on a potion for Bell's sake. I take Fell's small revelation as a serious injury flag. Someone is going to get hurt badly and they may not be simple to heal in the dungeon with a new potion.
Fells gives Bell another reason to get stronger, the Xenos interest. With more reasons to get strong, we can probably expect crazy growth. Fells also gives Bell a measure of how strong he must get, strong enough to reach the bottom of the dungeon. So stronger than any other adventurer. Up until now Bell's goal and motive to get stronger has been to catch Ains and stand side by side. To reach the very bottom of the dungeon and conquer it he will have to be stronger than her much stronger. Liaris freese works based on desire, the first part of this episode in contrast to the very first episode has made it very clear that Bell will and cannot stop getting stronger at Ains's level.
According to Fells a covenant that was forged and conclusion are at the bottom of the dungeon. That sound like he is saying the series could end when Bell reaches the bottom of the dungeon. But what about the Black dragon which comes first reaching the bottom or taking on the Black Dragon that roams the world freely?

Enemy Setup
Eina has two males fighting over her who she refers to formally.
Mr Luvis And Mr Dormul. Eina did not have to go out of her way to use their names and judging by their envy of Bell I believe we will see those two again. The anime wants us to know who they are.
Last season we got an inkling that Aina may like Bell but in the very first episode of the 4th season, it is made obvious that she likes him and she says she thinks she may be head over heels. I think this was done intentionally to set up a future interaction with those two from earlier Mr Luvis and Mr Domul clashing with Bell for Aina's love, they're too weak to pose a threat themselves so maybe trying to get rid of him another way.
I wanna talk a little bit about why Eina loves Bell, she's attracted to his growth not just in status but as a person. She also told Bell what may have been what she was attracted to however I think what she told him was partly to keep him alive. Eina was the reason Bell developed Liarse Freeze after his encounter with Ains she told him
"Listen, girls like guys who are strong, and can protect them. So if you keep working hard and get stronger, she just might like you back."
Just one episode ago last season, what did Bell do he protected Eina from Gros. Ironic that Bell ended up protecting her but what's more curious is that's not the only reason she fell for him. This is a key point Eina is not looking for a hero to save her she wants someone mature. To go back to when Eina took Bell to look for equipment she is only 19 but acts much older. That means that she has had to mature quite quickly so seeing those qualities in someone else might be attractive to her.
Hestia Familia Grow In Their Own Way With Their Own Limits
Let's start with Lillie
Just like Finn Lilli is a Primm and the smartest of in her bunch. She was the one reading the letter from the guild immediately after Hestia had opened it did Hestia even look?. Hestia gave it to Lillia as if she is saying here give it a once over I can't be bothered mentally and you're smarter than me anyway. Hestia immediately voices her lazy reason for choosing to be an exploration Familia adding to my point.
Even though Lili is a level 2 Daphne refers to Lilli as a level one supporter, not a level 2 not a level 3 and most definitely not a level 4 supporter. This is important because Lilli specialises in supporting level 1's the upper floors are where she is most knowledgable and what her equipment can handle. Lilli knows before Daphne says anything that the lower floors are dangerous for her but I don't think that's the reason she is down. I think the reason she is down is not that she is afraid of dying but of not being useful to Bell and left behind. Lilli is very smart and able to contribute to a plan that allowed the Hestia Familia to outwit Daphne and the Apollo Familia without even knowing the basics of being a strategist.
Welf's Finest
Welf straight up told everyone he had new equipment for them all regardless of whether the guild had issued a request or not. Last season although useful the magic weapons he made all broke, he must have been thinking about that. Going further back to Welf first joining Bell he needed to level up to obtain the Blacksmith ability. Welf's hands are bruised meaning that the equipment he whipped up is right at the limit of what he is capable of making at his current level. On one hand, whatever Welf has made besides Bells's is bound to be able to help tackle the lower floors. On the other hand, weapons still need users and when those limits are reached it's not like Welf can make something better than he already has to compensate.
Aisha Plot Convenience and Potential plot point
Lilli said she does not know how Aisha found out about the expedition perhaps the guild informed her, I hope there is more to it and it's not just plot convenience.
As we know from Bell's attainment of a Grimoire, they are very expensive so how Aisha got her hands on one could be a plot point for later. Haruhime's growth is new magic but as she states learning new magic is a complicated and time-consuming process and grimoires don't just get left in pubs, often, so much like Welf whatever she gains will be her limit for the time being.
Mikoto
I saved Mikoto's growth strategy for last because it ties into a point that I think will become more apparent as the series progresses in my opinion. Mikoto is told by Takemikazuchi that she is relying too heavily on Status and that Status does not go up every day. He then vocalised technique and breathing as a way to get stronger, things that can be improved more quickly than status through effort. Her growth is enough to learn a technique from Takemikazuchi that she could not before. This is a growth and also a limit no matter how good her new techniques are even if they allow her to oppose the strong her status will still limit her.

Takemikazuchi who has just the state of a normal human was able to defeat Mikoto however he was visibly tired. Why make such a point of showing us it's simply because the gods don't grow at all. He probably never used to get tired sparring with them. I thought that the gods call humans and demi-humans their children because they came from them but maybe it's because children do something the gods can't do, grow. Hestia brings the point home by saying all kids grow up. You have to wonder if Hestia who is scared of being abandoned by Bell fears simply being outgrown. Bell is outgrowing the whole Hestia Familia.

Mirroring Last Seasons First Episode
The ending of the first episode of season 4 mirrors the first episode of the season before it. The group is fighting on the same floor that they found Wiene a Xenos, the same floor that was their limit last season they are breezing through.
The very last ending was one hell of a cliffhanger it could have been Asterius a Xenos, pulling a person with torn-off leg to safety. I think it's another creature though possibly pulling the person for food.
An incredibly detailed episode every moment seemed relevant I hope you enjoyed the content and please share your thoughts without any spoilers of course.