How MTG Cards Are Printed: From Sheets to Decks Now lets look at the process
The power level on this one is roughly that of Phyrexian Arena Id estimate and given that a slower, less mana efficient Phyrexian Arena was one of the strongest card drawing tools in the last Standard (Underworld Connections), Id be very surprised if Sultai Ascendancy didnt prove to be very good in Magics most played Constructed format, likely as the best enabler for a delve-abusing Sultai midrange or control deck
Sadly, though, Virtue and Valor was not done well
This means that if a creature is tapped, it cant block attacks your opponents direct at you on their turn
You can't proliferate speed because it's not tracked using a counter on a permanent or player
You'll notice that this format also adds more Evolution strategies to the format, taking advantage of the new GX mechanic introduced in Sun & Moon to bring Stage 2s to the forefront of the metagame (that aren't just Greninja or Vileplume)