The theoretical impact of its ban would be a 2/5.
P/T Number 444 Language English Legal Formats Commander, Legacy, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Modern, Pauper, Pioneer, Standard, Timeless Rulings (10/2/2025) The Destined White Mage's second ability triggers just once for each life-gaining event, whether it's 1 life from Al Bhed Salvagers or 3 life from Balamb T-Rexaur
Here at TechRaptor, my colleagues and I have previously checked out the Starter Decks for Ursula's Return (linked above), as well as the Rise of the Floodborn set and the Into the Inklands set
So long as you can pump Sisy up high enough, theres nothing you cant get, no matter the situation