This isn't exactly a gym leader though it is a boss so I'm asking anyway!
It's the double battle you Vs. Zel and Taka in the Beryl Ward by the PULSE.
--Your current team-- [Frogadier] | [25] [Hold Item: none] [Ability: Protean] [Nature: Hasty] - Water Pulse - Round - Lick - Grass Knot
[Trapinch] | [25] [Hold Item: none] [Ability: Arena Trap] [Nature: Adamant] - Bulldoze - Feint Attack
- Rock Slide - Mud-Slap
[Gloom] | [25] [Hold Item: none] [Ability: Stench] [Nature: Hasty] - Acid - Poison Powder - Mega Drain - Sleep Powder
[Kirlia] | [24] [Hold Item: none] [Ability: Synchronize] [Nature: Modest] - Confusion - Charge Beam - Magical Leaf - Double Team
[Growlithe] | [24] [Hold Item: none] [Ability: Justified] [Nature: Mild] - Fire Fang - Take Down - Reversal - Odor Sleuth
[Panpour] | [10] [Hold Item: None] [Ability: Gluttony] [Nature: Quirky] - Cut - Lick - Leer - Water gun
(Need for Cut)
---- --Other Pokemon you have in your PC-- [swirlix] | [24] ---- Additional useful info such as money available, items you currently may have if they're relevant etc. 2x Super Potions
9x Potions
5x Every Status Healing Item
Zel's Pokes:
1 Glaceon
2 Espeon
3 Umbreon
Taka's Pokes
1 Lilep
2 Tangrowth (Mega)
3 Chatot
Welp, got any ideas guys?