Which weapons can each class use? Three aides revealed, and why mages need melee optionsMinor spoilers
Classes determine weapon access, separately from proficiency bonuses. Magic has limited uses, so giving mages suitable melee weapons lets them keep finishing enemies and earning EXP.
Original video: “Class-locked weapons, three aides revealed, and new battle footage: Early July official X updates for Fortune's Weave” | Bilibili creator Fenghua Chuixue ACC.
The three aides' identities and factions
Introductions have now been revealed for 
Fabio on 
Dietrich's team, 
Bonaventure on 
Theodora's, and 
Buccar on 
Leda's.
Fabio comes from Fódlan's subterranean people and enjoys talking with intelligent people. He looks eccentric but has plenty on his mind. At the reveal, this made me lean toward a prequel: every route in the older game badly damaged that faction, so a sequel would need to explain its recovery. Setting it in the past also avoids choosing a canonical ending for the older game. The dark-magic clip's circle resembles the earlier game's too, keeping me interested in the connection between the regions.
Bonaventure is the queen's trusted aide and the historian of Salamis. Because the nation forbids writing, he keeps its history in his head. Why prohibit writing? Could it involve controlling or concealing history? Those questions interest me more than simply labeling him a strategist. The clip shows him using wind magic and swords against a dead army with Underworld Boon, testing both damage and weapon preparation.
Separate Buccar's sources of damage reduction
Buccar knew Leda's father long ago and has served the family for over twenty years. He occasionally calls Leda a princess. That adds a family mystery to his role as her protector.
The combat clip gives him 
Shielding Axe and a shield, fitting a front-line setup. His personal ability 
Guardian’s Duty actually reduces incoming damage to 90% and does not require standing near Leda. Consider the personal ability, weapon, and shield separately instead of attributing every reduction to one effect.
The arena's pipes, wires, and towers also stand out. Whether ancient ruins connect to these facilities is another clue I want to follow.
Weapon access is separate from proficiency bonuses
Different classes can use different weapons. Everyone cannot simply pick up a bow or fight with gauntlets, giving class changes real significance.
Soldier's description lists swords, lances, and axes, while the clip lists proficiency bonuses only for lances and axes. Actual access includes all three: swords, lances, and axes. EXP bonuses are separate from weapon access. A missing EXP bonus does not mean you must choose only two of the three weapon types.
Even ordinary spell attacks consume uses, unlike normal melee weapon attacks, which cost no durability. Give mages a melee weapon their class can use so they can keep finishing enemies and earning EXP after spells run out. Bonaventure's sword and 
Tialla's lance illustrate this approach.