New players know what the English words Flying , Haste , Vigilance , and Intercept or Block mean, but they may not understand they're mechanically significant to the game
The more X-spells you cast, the less mana Rosheen produces for subsequent X-spells
If your creature isnt a human, then its more powerful than it seems (cards like Lost Legion and Ogre Errant are extra powerful, since they benefit from both knight synergies and nonhuman synergies)
On the other hand, the backsidea new Epharais one of the strongest Enchantresses we've ever seen, as a 4/4 lifelink indestructible creature (assuming you have three enchantments, which you should in a deck that would want Invasion of Theros) that draws a card each time you play an enchantment
He's just worse than pretty much any other yellow leader and the cards that come with this deck don't really make up for that