Having a strong Adventure bumps up the card, but its still good at five mana
For regular upgrades I highly recommend: Vito, Thorn of the Dusk Rose, Mondrak, Glory Dominus, Anointed Procession, Parallel Lives, Eerie Ultimatum, and you can also run the Cat Oven combo with Cauldron Familiar + Witch's Oven + Clock of Omens, and there's the Ballista Combo Heliod, Sun-Crowned + Walking Ballista, and finally the Exquisite Blood Combo since the deck already runs the other piece Sanguine Bond One Down, Three to Go
Sigarda, Champion of Light is the newest incarnation of the much-loved Innistrad Angel
I could see a version using discard on turn one both as disruption and to see what they need to answer and then Discovery to actually find the answers or finding and setting up a fast Tasigur or Gurmag Angler
Since Simic typically loves ramp, this seems really strong there