I don't do much MLP because I suck at getting their style right, and also, I don't draw horses a lot.
(Was slightly lazier on Ruby lol)
Meet Sapphire, the mythical guardian of Sapphires and Water, and his younger more feisty sister Ruby, the guardian id Rubies and fire. They're deity Alicorns. They might be opposites but they can never be any closer.

Name: Sapphire (Fire Ruby calls him)
Occupation: Deity/Guardian
Element: Water
Cutie mark: Sapphires
Gender: Male Colt
Age: N/A (Adult)
Pony type: Alicorn
Loves: His sister, Swimming, manipulating the oceans to his will, he's a positive rolemodel for his sister. Blue things.

Hates: Bullies, Pranks, Injustice

Name: Ruby
Occupation: Deity/Guardian
Element: Fire
Cutie mark: Rubies (Red version of Sapphire's)
Gender: Female Pony
Age: about 500 years old (Child Deity)
Pony type: Alicorn
Loves: Volcanoes, pranking her brother at times, especially when she's waking him up. Spicy food, racing, playing with Dragons.
Hates: Water, cold places for long, anything who takes her brother's attention away from her. She might hate water but she'll always love her brother.