Lightning is one of the few characters who comes with innate Dual Wielding. Which is to say, Lightning can strike twice.
Orlandu is more beneficial with the greatsword that has the holy element, with Excalibur being the most beneficial since it have highest attack for holy greatsword. It also happens to be his Starter Equipment in his home game.
Why don't Lid and Jake have Elemental Powers even though from their outfits' color alone it should be obvious that they're meant to represent Earth and Wind respectively? Two reasons: 1) Rain and Lasswell had already taken Stone and Aero spells into their repertoire, and 2) They're coming from countries where technology is more dominant than magic and nature, thus preventing them from attuning themselves with a specific element. Lid's Invention and Jake's various Laser skills and Limit Bursts? All are products of Magitek.
Expanding to this, why does Nichol, the dedicated Water-elemental party member, have both Blizzard and Water spells? Because Ice Magic Is Water, and Lasswell is too physical-oriented to utilize his own Blizzard spells properly.
Sakura, the Thunder specialist, has both Light and Dark offensive skills to compensate Fina's lack of offensive White Magic before she hits 6-Stars form, and Dark Fina's status as Rare Summon that prevents her from being a proper Dark-elemental party member. This also serves as a Foreshadowing to her exact relationship with both Lightlord and Darklord.
It might seem odd at first, near the end, that Raegen is outmatched by Sol in the endgame, when Veritas of the Dark is capable, with the right equipment, of soloing the fights against Sol. However, remembering the previous chapters has this make sense - the armors of the Sworn Six of Paladia are all power amplifiers, and the real Raegen no longer has his. If, like the vision version you can summon, Raegen still had it, he probably could have stopped Sol without the measures that were ultimately required.
In-game, Akstar calls Lasswell's Mirror of Equity terrible to demonstrate how weak he is. Mirror of Equity, despite being Lasswell's signature ability in-story, is only marginally stronger than his regular attack. In fact, it can be taught to anyone with Odin or a friend point unit's Trust Mastery Reward.
The Revolving Saw, Conrad's Trust Mastery Reward, says that "controlling the speed of the saw requires extensive training for use, even by veteran mercenaries." It is a 2-handed Greatsword, and Conrad shares a banner with a certain mercenary from the Final Fantasy franchise, who has a strong reliance on double-handing 2-handed weapons. In short, the description flat-out implies "Use this on Cloud."
The fact that Hyoh of the Delta Star, in all of his battles, is highly vulnerable to an A.I. Breaker is well-known to many players. That said, later revelations do shed light on this issue. Given that Hyoh is actually Rain, it makes perfect sense that he demonstrates a fatal flaw in his battle style for both his father and his best friends to exploit - he wants to give them an easy way to win without being too blatant about throwing the fight.
One of the "One Year Anniversary" bonus dungeons involves battling King Kupo, for points that can be turned in for bonus items. But then you realize... He shows up, expecting to play, and you're just there to beat him senseless. Or insult him until he starts hitting you. You bastard.
Cerius, one of the Visions that is able to be summoned, comes from a "nation of mages". She later ran away, tired of killing people, and was assassinated by agents of her homeland. This seems like a generic tragedy until you realize who Mysidia's leader is. Suddenly, Sakura's morals become much more questionable.
Similarly, Lotti and Macmedi's backstories involve Lotti being exiled from Mysidia due to her lack of magic, while her grandfather Macmedi left willingly to take care of her in exile. Sakura's unwillingness to allow non-mages to live in Mysidia directly contributed to her sister Citra's mental breakdown when Lotti and Macmedi were killed, kickstarting Season 1's plot.
In their respective story events, Ilias and Helena reference "the legendary Mel" and "the legendary Montana". Both "legendary units" are 2-star friend point summons who are a 3-star base at max. Helena and Ilias are both 4-star bases who can reach 6 stars at max.
This actually goes right back into Fridge Brilliance territory: Helena's story in the limited event showed she wanted to not only discover Montana's legacy but create her own, so it's fair to say Ilias felt the same way. What better way to show them become better than the legends they admire but by making them stronger units that effectively used the legends as foundations for their growth?
Duke and Ryunan share the same dynamic. Ryunan is revealed to be Duke's ancestor and the original sealer of the dragoon. Ryunan is a 5-star max, while Duke starts out as a 5-star, but this is lampshaded as Ryunan already acknowledges Duke's humility.
Veritas of the Dark is explicitly described as the version who attacked Rain. It is later revealed that Veritas of the Dark is a Vision of Raegen summoned by Veritas of the Light. In effect, this makes him a Vision of a Vision.
Given how Veritas of the Dark gets to do his own thing and pulls his own surprises even on Reagan, despite being based on him, AND Light Veritas, despite her summoning him based on her memory of him from the war, it's more than likely that the armor and/or Light Veritas's sheer power and will made him somehow become more of his own being.
Also, while a Vision of Veritas of the Light is available in the gacha, the game makes it clear that the one who summoned Veritas of the Dark as a Vision is the original. It's even a plot point in Season 2.
From a gameplay perspective, it makes sense that the various slab and statue enemies are not immune to petrify, given that they're still Demonic Spiders even with those tricks. But if you think about it logically... they're already made out of stone. Why does turning them into stone kill them?
They've been turned into mundane stone that doesn't move.
While the reason that it doesn't happen (namely, nobody ever told Citra that it'd even be a possibility) makes sense, the entire subplot about whether or not Yego should use the bomb implanted in her to make a Heroic Sacrifice against the Emperor of Aldore leads to the realization that they could have just summoned another copy of the character in question, which would have had the same abilities as the original and thus the Vision could have used the bomb implanted in her, leaving the original Yego fine and dandy. Moreover, the person privy to the plan, namely, Cid, already knew that Citra could summon a duplicate of someone and have it operate at the same time as the original as one of the major plot twists in the first season is that Citra already did so with Raegen, which was revealed when Raegen clashed swords with the vision of himself. Particularly as the Emperor notes such a plan would work after Cid abandons it, it makes it appear particularly foolish that nobody tried to talk to Citra to come up with a version of the plan that would work without a proper Heroic Sacrifice.
