The Prime Merlinean is a powerful Merlinean conjuror destined to become the successor of Merlin and the only one who can help his allies to defeat Morgana le Fay and her Morganians. This individual known to be a Merlinean with immense powers due to being powerful from within to the point that they not need any magic rings or catalyst to use their powers.
They also countered by The Beast, a monstrous entity with immense power that formerly a sorcerer turned to the dark side.
The Prime Merlinean is believed to be a direct descendant of Merlin's bloodline. Because of this, that person's magic was immense, even surpasses any known sorcerers in existence. Even said also more powerful than Morgana le Fay herself, which is why Merlin said that only the Prime Merlinean can destroy Morgana. He/she can also tap the ability to cast magic without need of catalysts, something that give him/her better advantages in the battle. However, to unlock this ability, they must became very powerful from within.
The depiction of the Prime Merlinean in The Steampunk Adventures of Sorcerer’s Apprentice was not so different with the one in the original movie, but has one additional power: He/she could absorb other beings' magic and had it turned against their users. But the only thing that made them different with other sorcerers are same with the movie: He/she can only identified as a Prime Merlinean by the power within the Dragon Ring.