Have the Steam version of FF7 and:

1. Install 7th Heaven's Mod: https://7thheaven.rocks/
2. Install New Threat Mod (1.5 or 2.0, I hear you can do it on both versions, but I only tried 2.0)
3. Play until Aerith's iconic scene.
4. In NT MOd, the Boss will revive Aerith Mid-battle.
5. DON'T KILL HER
6. Enjoy~