For whatever contrived reason you want to put in place, the ShinRa corporation has discovered the Spencer Estate in their world and decided all threats within it must be neutralized. TO accomplish this goal they send in SOLDIER 1st class Zack Fair, armed with his trusty Buster Sword, and a thunder, blizzard and fire materia. He encounters his opponents in the following order:
1. 10 Zombies
2. 5 Cerberus'
3. 5 Crimson Heads
4. 5 Hunters
5. Plant 42
6. The Yawn
7. The Black Tiger
8. The Neptune
9. Tyrant T-002
Special Bonus Round(as it isn't in RE1): The Nemesis
Gender: Male Location: In Luna's mane, chasing STAAARS!
He will have trouble with the Nemesis that's for sure. Took a laser cannon to bring that thing down. 10 zombies? The number of the undead has to be bigger if you want this to be a challenge. Just saying.
Zack clears the entire gauntlet since the mutants of RE1 aren't any more challenging than what he's faced already. His only challenge is Nemesis but even he won't be much of a problem especially with materia being used.