Sunburst

Sunburst is a male unicorn pony, Starlight Glimmer's childhood friend, and royal crystaller to Flurry Heart. He first appears as a colt in a flashback in The Cutie Re-Mark - Part 2, and he appears as a full-grown stallion in present day in the season six premiere.

Development and design
Sunburst bears different resemblances to S04E12 Unnamed Unicorn Stallion #1 and Gaffer.

Sunburst's name was previously used for a G1 Earth pony boy.

Depiction in the series
In The Cutie Re-Mark - Part 2, Starlight Glimmer takes Twilight Sparkle and Spike back in time to her youth. They witness young Sunburst and young Starlight playing a book-stacking game, but young Starlight's move almost makes the books topple over her. Sunburst saves her by using telekinesis to put all of the books back on the shelf. It is this moment that earns him his cutie mark. After which, Starlight loses touch with Sunburst and, because he earned his cutie mark before her, she starts believing that cutie marks tear all friendships apart.

In The Crystalling - Part 1, Starlight says that Sunburst "knew everything there was to know about magic" when they were foals and would occasionally help her along in her magic development. When Starlight later approaches him in the Crystal Empire to reconnect with him, he acts mainly awkward around her, purporting to be an important wizard.

However, it is later revealed that, although Sunburst is very knowledgeable about magic, he is untalented at casting it. He uses this knowledge of magic to help Starlight and her friends restore the Crystal Heart and complete the newborn baby Flurry Heart's Crystalling ceremony. Following this, Sunburst is appointed as Flurry Heart's "crystaller" and magic advisor.

Quotes
"S-Starlight! My goodness, it-it's been a long time!"

- The Crystalling - Part 1

"So... the Princess of Friendship wants you and I to be friends again?"

- The Crystalling - Part 1

"I know Princess Twilight is keen on the two of us rekindling our friendship, but... it's been so long."

- The Crystalling - Part 2

"No rest for the wizardly."

- The Crystalling - Part 2

"You know, I'd like to help, I-I really would. I-I just have so much, um, important wizard work to do around here."

- The Crystalling - Part 2

"I'm not an important wizard! I'm not even a wizard at all!"

- The Crystalling - Part 2

"Reading about magic is one thing, but you don't know what it was like at magic school! To know so much and not be able to do any of it!"

- The Crystalling - Part 2

"Did you really travel through time?"

- The Crystalling - Part 2

"Like I'd ever lose touch with my oldest friend."

- The Crystalling - Part 2