{PS2} (Berserk Charge Strat) KH2FM Data Roxas Level 1 Critical Mode Speedrun
Credits to Mace30 and CrispyMe for this strategy
The window for the stunlock is slightly easier to hit for this fight, as the keyblades do help keep Roxas stunlocked for longer. Even then, the timing is still pretty strict.
The other challenge for this is using up your MP and getting Roxas into the air for the stunlock without hitting his revenge value or having him retrieve his Keyblades. Eventually I found that just spamming Ars Arcanum to drain MP helps, without doing all of the RCs.