I'm probably not the best authority since I basically played Yuffie as if she was Tifa instead of properly learning to play Yuffie (hence the Reddit post). Since Sonon is not directly controllable in Intergrade, I use him as a support character. He carries the time materia to ensure Yuffie is hasted as much as possible, as well as the barrier materia to reduce physical damage. He also carries a maxed healing materia. He does not need revival materia due to his auto self-sacrifice skill. Instead, Yuffie carries the Revival materia so she can ask Arise on Sonon after he uses self-sacrifice. In this build, Yuffie is a physical attacker while Sonon is a magic caster. The core of this build is the synergy-lightning materia link on Sonon along with the Djinn Staff and Magic-up materia. My goal is basically just to use Art of War as many times as possible to trigger as many casts of lightning as possible via Synergy materia. To this end, Yuffie should always be hasted and support/healing should be relegated to Sonon as much as possible. As well, barrier + steadfast block materia means Yuffie can farm a lot of ATB without taking much damage just by guarding Bahamut's regular and frenzy attacks. Note that she must still dodge Umbral Strikes and they are unblockable. For the first fight, you basically just focus Bahamut as much as possible and take him down before megaflare. Even when Ifrit is summoned, you continue to focus Bahamut and more or less just try to avoid Ifrit. I save all my mana for Healing and Arise and deal primary physical damage + free synergy spells. The second fight is all about getting to limit break and killing Ramuh quickly. Ramuh is relatively squishy compared to Bahamut but puts out larger AoE attacks that deal tons of damage. I don't even bother taking out the summoned sparks - just bum rush Ramuh and he should die before you do. Pride and Joy 0.5 is just an enemy you have stay close to. If you go too far away, P+J will hit you with Beam cannon which pretty much one-shots you. Mercifully, P+J has a lightning weakness which is why were are carrying synergy+lightning on Sonon and elemental+lighting on Yuffie. Again, no special strategy here. Just do your best to stay behind P+J to avoid getting stunned or beam cannoned. If P+J manages to grab Sonon, make sure you target the arm to free him. You can do this more easily by using lock-on targetting. Good luck!