In addition to the shielding on her embrace, Seraph's major benefit is Consolation, which is a 300 potency heal with 100% shield that she can use twice. This is almost the equivalent of two free deployment tactics adloquiums, which is also a 300 potency with a 125% shield. So the shield is a little weaker (and can't be recitation'd), but that's still pretty powerful. The whispering dawn and illumination equivalents are just there because Eos had them, and Selene is just a skin-suit she sometimes wears so Seraph might as well have Eos's abilities.