Illumise leads a flight of illuminated Volbeat to draw signs in the night sky. This Pokémon is said to earn greater respect from its peers by composing more complex designs in the sky. With its sweet aroma, it guides Volbeat to draw signs with light in the night sky. Its fragrance attracts a swarm of Volbeat, so they draw over 200 patterns in the night sky.
Pokédex entry #314
Illumise is a type bug Pokémon that doesn't evolve
Illumise in Pokémon GO
It's possible to hatch Illumise from an egg?
No, Illumise can't be hatched.
Which are Illumise’s strengths and weaknesses?
Illumise is a bug type Pokémon. bug type pokémons are strong against grass, poison, psychic pokémons but weak against fire, fighting, flying, ghost pokémons.