Luvdisc

The Emerald Pokedex entry states that giving a Luvdisc is a way to express one's feelings of love. Placing this Pokemon in the gym of a mortal enemy may yield... unexpected results.

The Sapphire Pokedex entry states that any couple that comes across a Luvdisc is promised a loving relationship that never ends. Luvdisc may make playing in water biomes a great first date, perhaps with that mortal enemy from earlier? ( ͡° ͜ʖ ͡°)

Best PvE Offensive Moveset

• Water Gun should be paired with Water Pulse for Water-type coverage.
• Aqua Jet is a decent alternative, with slightly worse cycle-DPS.  

Best PvE Defensive Moveset

• Water Gun should be paired with Draining Kiss in order to charm foes into submission. This is by far Luvdisc’s most effective moveset.

Luvdisc is pretty much worthless in PvP.... just like in PvE.