Because RUclips is deleting random comments for some reason (and for those who are too lazy to read the video description)... For those who are wondering: Normally, you start off this fight with no AF meter. If you bring units such as Flammelapis AS, Aldo (with 2 other light units) or, in this case, Izuna with her stellar unlocked, you can start off with AF meter. Soira AS also has a passive where she regenerates 10% of the AF meter at the end of each turn.
Because RUclips is deleting random comments for some reason (and for those who are too lazy to read the video description)...
For those who are wondering: Normally, you start off this fight with no AF meter. If you bring units such as Flammelapis AS, Aldo (with 2 other light units) or, in this case, Izuna with her stellar unlocked, you can start off with AF meter. Soira AS also has a passive where she regenerates 10% of the AF meter at the end of each turn.