Why can Incineroar learn Leech Life/Umbreon learn Psychic?

Question

Part 1: Leech Life is a move that steals HP. How does Incineroar have the ability to perform that action?

Part 2: ...What the heck. Umbreon can learn Psychic??? How in ALOLA is that possible? Dark type learning Psychic move. Just like Fire/Dark type learning Bug type move. (Fire types learning Solar Beam have an exception!)

Can anyone follow up on how these two moves are possible?

Comments

I actually find Fire types learning Solar Beam and even Fire types having Solar Power a greater stretch. A Fire type LOOSING health in warm conditions? Pokémon like Charizard should of had Flash Fire, not Solar Power, with Flash Fire being automatically triggered by 'intense sunlight' (of course, this would require some fine tuning, as that would be BRUTAL). This move, and this ability seem to me to suit only grass types, but that's just my opinion.

Answer 1

Leech Life is based on fangs and sucking blood like a vampire (although admittedly the Litten family doesn't have the biggest fangs). Incineroar is a Dark type, and sucking blood is a pretty messed up thing to do. The move is probably a Bug type because it may have originally been based on paralysis ticks, but is more generalised as being based on vampires instead (i.e. Zubat family).
As for Umbreon and Psychic:
Pokedex for 'Y', 'B/W2': When exposed to the moon's aura, the rings on its body glow faintly and it's filled with a mysterious power.
Pokedex for 'B/W', 'Platinum': When exposed to the moon's aura, the rings on its body glow faintly and it gains a mysterious power.
Psychic could easily come under a general heading of 'mysterious power'.