Since we now have an Elite 4, a few things have changed from the old level 100 gyms, this will help you reach the Elite 4.
To have the ability to challenge the Elite 4 you first must have completed all 8 npc gyms.
The Gym Rules: https://www.pixelmoncraft.com/gym-rules
Rock Gym, level 20, /warp rockgym
Water Gym, level 30, /warp watergym
Electric Gym level 40, /warp electricgym
Grass Gym level 50, /warp grassgym
Poison Gym level 60, /warp poisongym
Psychic Gym level 70, /warp psychicgym
Fire Gym level 80, /warp firegym
Ground Gym level 90, /warp groundgym
Once you have beaten all 8 gyms you can now challenge the Elite 4. The rules are the same as the gyms but you must use the same team for all 4 of the elite 4, you can battle them in any order and there is no level cap.
The Elite 4 /warp elite4
Ice/Ground /warp iceelite4
Fighting/Poison /warp fightingelite4
Ghost/Fairy /warp ghostelite4
Dragon/Steel /warp dragonelite4
If you manage to beat all the Elite 4s you will be able to battle the champion npc, if you win against the champion you will become our newest champion. The newest champion will get their team as the new npc champion that new hopefuls will need to beat to become a champion. If you lose you do not lose your progress and can try again.