>>19355916>>19356026I'm not usually one for hamfisting Legendaries into everything but Groudon and Kyogre's battle causing a massive global semi-literal shitstorm would be pretty neato. Legendary Pokémon free-for-all, Lugia and Manaphy getting involved with Kyogre, Heatran backing up Groudon, Zygarde showing up with Rayquaza to slap everyone's shit, etc.
Speaking of Manaphy I'm pretty sure Hoenn qualifies as tropical enough for Phione to live
>>19358836>Doesn't Diantha have the highest leveled team of any Champion battle?Blue - 63 (Rematch: 75)
Lance - 50 (Rematch: 75)
Steven - 58 (78 in Emerald as bonus boss)
Wallace - 58
Cynthia - 62 (Rematch: 78) (82 in BW2 Challenge Mode as bonus boss)
Alder - 77 (Post-game only)
Iris - 59 (59/63 Challenge Mode) (Rematch: 78/83 Challenge Mode)
Diantha - 68 (80 as Grand Duchess in Battle Chateau with Black Writ of Challenge, but only 4 Pokémon)
Diantha does indeed have the highest leveled team, but she suffers badly from both poor team composition and the EXP Share being broken as hell so most players have a full party of Level 80 Mons by the time they reach her.
All things considered, Cynthia is still probably the most difficult proper champion.