Look at the Archmage and Rennyn. Both have the "same" attributes, both cards are Legendary, the bonus of the Archmage is the Dragon Splinter.

If you now compare Julian with the other 2 Mana Splinters, you will notice that they have the same attributes, but the 2 Mana Splinters are a rarity level among Prince Julian. Either the epic 2 Mana Splinters are too strong, or Prince Julian is too weak.