I'm only getting 1 exp when defeating a battler, pls fix naow!
You are playing hard mode and have reached the level cap. This will scale down exp to 1 to prevent overleveling. beat more gym leaders and major battles to have it increase.

What are Natures?

Natures increase a stat (such as Attack, Special Attack, Speed, etc.) by 10% and decreases another by 10%. For example, Modest increases Special Attack and decreases Attack, allowing Special Attack Movesets to benefit from the lack of Physical Attacks even further, while Adamant or Jolly is suited for Physical Attack Movesets, such as Tyranitar with Earthquake, Garchomp with Dragon Claw, etc. Natures include:

Jolly (+Speed -Sp. Atk)

Adamant (+Atk, -Sp. Atk)

Modest (+Sp. Atk, -Atk)

Timid (+Speed, -Atk)

Other common natures are Sassy, Relaxed, Hasty, Bold, but there are many others.

Detailed Explanation of Natures

What are IVs?

Individual Values or IVs are the genetic code of Pokémon, similar to your DNA. They have a maximum of 31, and are used to calculate the value of a stat, but basically, the higher the IV, the higher the stat becomes. In both regular games and Pokémon Insurgence, achieving specific IVs require breeding, though in Insurgence, an item, the IV Stone, makes the Pokémon have a perfect IV.

Detailed Explanation of IVs

What are EVs?

While IVs are genetics, Effort Values or EVs are obtained through training. EVs are similar to Exp. Points, but instead of contributing to the Pokémon's level, they directly contribute towards a Pokémon's stats. The maximum EVs a Pokémon can acquire for a stat is 255, with 510 EVs in total among all stats, but EVs increase the stat by 1 on an increment of 4, so the 3 last EVs would be wasted, and thus, usually the optimal EV distribution is 252/252/4 on 3 different stats, while the remaining 2 EVs are useless.

If you battle a Bulbasaur, you obtain 1 Sp. Atk EV, but battling an Alakazam gives you 3 Sp. Atk EVs. Using the Power Lens while fighting Alakazam, you obtain 7 EVs (3+4), and if the Pokémon has Pokérus, this is doubled to a total of 14 EVs. Therefore, to achieve an Sp. Atk EV of 252 through fighting Pokémon that give 3 Sp. Atk EVs, you must battle it 18 times (with Power Lens + Pokérus), or 84 times without Power Lens or Pokérus.

Power Items (available at the Helios Department Store) also help with EV training as they add 4 EVs of a certain type to the amount you would normally gain.

Pokérus, a rare status condition, doubles the amount of EVs you get from a Pokémon.

Detailed Explanation of EVs

List of Pokémon by EV yield