Intrigued by the new turn into blue/black/green! I think this is shaping up really well!!!

A few thoughts:

I think you might speed up the deck a lot by getting rid of the two Avatar of Might and just running 4 copies of Hunted Phantasm. That's the best card in the deck! Avatar is the only card on the list that can't just be played when drawn. There's a condition that needs to be met. The rest have no condition and should come out on the field ASAP.

Swan Song and Strix Serenade are both fantastic for the deck and strictly better than Into the Flood Maw which you have in right now. Amulet of Safekeeping is also kind of a dead/do nothing card, because it sits on the field and provides passive support. I think you should swap those pairs of cards.

Blood Seeker is a worse Blood Artist in exchange for 1 power and I don't think that's worth it to you. I think you should replace that with one of the blue 1 mana instant draw spells -- Brainstorm, Opt, something like that. It will get more cards into your hand and make your play faster! The more card draw you have, the more likely you are to hit Blood Artist at all to get her onto the field!

Also those two legendary lands are awesome, but not worthwhile in this deck. You're running 3 Prismatic Vista with exactly 3 basic lands in the deck. You draw those lands and all three vistas become a dead draw. You need basic lands. You need fetchable lands at least. There are basic dual lands out there! Put in some Swamp/Islands, Swamp/Forests, and Forest/Islands instead. I still think you should take out the Cavern of Souls in favor of colored mana-generating lands as well. So many of your cards require 2 colored mana, after all!

Excited to see where you take the deck from here!!!