this suggestion is simple, and isn’t even original. gamefreak themselves put red in gen 2, as an optional boss battle. I feel as though adding red in as an easter egg, or an optional boss battle would add a fun feeling of nostalgia. perhaps he could be hidden outside of the pokemon league, as if he’s about to challenge the league himself. his team should be taken out of the manga, as that’s my favorite version of red, although pokemon origins red would be cool as well. he should function similar to how the elite four and champion are said to function, with him using hyper competitive strategy’s. perhaps beating him could yield a reward greater than money, such as his hat, a unique mega stone, access to an entirely new area, or a secret ending. I realize theres a high chance this will be over looked, and even if it is noticed, it will most likely never be added to the game, but I feel as though a suggestion should help the devs think, and even inspire a new mechanic or feature. whatever ends up happening to this suggestion, I hope it helps in the long run.
That would actually be pretty cool. I have this Red team I designed a while back and I think it is a good boss.
Pikachu @ Light Ball
Ability: Lightning Rod
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk / 30 Def
- Thunderbolt
- Hidden Power [Ice]
- Substitute
- Encore
Gyarados @ Lum Berry
Ability: Intimidate
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Dragon Dance
- Waterfall
- Crunch
- Earthquake
Espeon @ Choice Specs
Ability: Magic Bounce
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Psychic
- Dazzling Gleam
- Shadow Ball
- Trick
Aerodactyl @ Life Orb
Ability: Unnerve
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Pursuit
- Earthquake
- Aerial Ace
- Stone Edge
Venusaur @ Venusaurite
Ability: Chlorophyll
EVs: 248 HP / 96 Def / 144 SpD/ 20 Spe
Bold Nature
IVs: 0 Atk / 30 SpA / 30 Spe
- Giga Drain
- Sludge Bomb
- Synthesis
- Hidden Power [Fire]
Snorlax @ Leftovers
Ability: Thick Fat
EVs: 188 HP / 144 Def / 176 SpD
Careful Nature
- Curse
- Return
- Rest
- Earthquake
This team is fairly balanced, making you fight both offensive and defensive opponents.
If you guys did not know, Red is a boss in Zeta and Omicron so I feel a bit mixed whether they will introduce him again 
perfect. only op if youre a noob. wait… um…well…uh… good luck buddy!!
They could always have gold/ethan
true, but id rather have red.