i have beat the boss and got the ruby but now im stuck because when i go to death mountain i can only stay in there for like 30 seconds

I introduced a friends cat for an evening to my 2 sister kitties Ruby and Scarlet- that have always been the best of friends. Ruby freaked out- and is now mad and hissing at Scarlet. What made Ruby turn on Scarlet and how do I reverse this?

Not hacked

Empoleon lvl 74 wave incense (starter)
Hydro pump
surf
waterfall
Hydro cannon

Charizard lvl 72 exp share (fire red migrate)
fly
flare blitz
heat wave
flamethrower

Sceptile lvl 71 rose incense (migrated from ruby)
leaf blade
iron tail
leaf storm
slam

Darkrai lvl 72 quick claw (previos nintendo event)
roar of time
spacial rend
nightmare
dark void

Palkia lvl 100 lustrous orb (spear pillar)
Earth power
aura sphere
spacial rend
surf

Raikou lvl 100 quick claw (migrated from fire red)
thunder bolt
crunch
thunder
hyper beam

dont yell at me if i did something bad for a pokemon s move just tell me what to change

Which names do you like best??
Boy:
Shaman
Oliver
Cruz
Harley
Bow
Blaze
Storm
Ty
Pheonix
Cooper
Jett
Pax
Shiloh

Girl:
Ella
Sadie
Harley
Maddyn
Ruby
Molly
Maddie
Tess
Chelsea
Willow
Shiloh
Jayla
Autumn
Mia

Thanks!! :) I know it s not a baby...but it s going to be my baby and I was am just curious to see what you all think!