I'm starting to feel that Loki can't Control his DF, it should be treated like a different Character,
Loki without his DF have Two Fighting Styles based on Adv. CoC + DF Powers (Ragnir),
Similar to how WB, Kaidou & Big Mom also have Two Fighting Styles,
When Loki Transforms, He basically becomes another Character completely,
A Beast Warrior who fights with Extreme Violence, Immune to Pain with High Endurance,
I believe My First Guess is True, Elbaph DF turns you into God of Berserkers,
In other words, Loki didn't Transform into a Dragon or Wolf or Snake, He became a Bear,
He is basically Volibear (From League of Legends) of One Piece, and it's fitting that Elbaph DF belongs to OG Elbaph (Who represents Odin),
And Odin was indeed God of Berserks, who can Awaken such Army,
That's what Galleila is for, Loki can turn them into his Berserker Army,
And you want a Hint from Start of Arc? Look at Human Loki Followers in Underworld, They wear Animal Skin which makes them look like Berserkers, hinting at who Loki truly is,
This is how I imagine Loki to be: