Even though he was very young, he’ll never forget his roots. Maybe it’s the power of an alicorn memory, or maybe it’s the kind of trauma that lingers forever. He wishes he could just forget, just move on… but he can’t. It’s truly embedded in him forever. And for that he’s angry.
If you’re confused or just new to the party, Panther was abandoned by his mother, Princess Luna, when he was about 6 years old. Luna raised him in secret for the first few years of his life, concealing his existence with magic and good old fashioned secrecy. No one knew of Panther’s existence, and all he ever knew was his mother. Panther is King Sombra’s son, and Luna couldn’t face banishment again for being involved with him. She’s the one who allowed him entry into the Crystal Empire, and if anyone found that out…
She loved Panther, but she was scared. If Panther were gone, her problem would be solved, and she wouldn’t need to keep such a big secret anymore. So they traveled together, far to the edges of Equestria and beyond, until they were in unmapped territory. She left him there, promising she’d be back soon, but of course she never came back. It pained her, but to pretend he never existed was the only solution. She knew he would die there, alone and cold.
But he didn’t.