Orazca Puzzle-Door and Hermitic Nautilus are a couple of examples of new blue cards from The Lost Caverns of Ixalan that you can use to craft with two other nonland permanents with activated abilities for the card to transform into Locus of Enlightenment
The biggest downside to playing sweepers when youre playing creatures is that whenever youre ahead on the battlefield, the sweeper is a dead card in your hand
Ixhel, Scion of Atraxa Ixhel, Scion of Atraxa isnt only a reliable way to give players poison counters, it also has a very powerful ability once those counters start to stack up on your opponents
Its a bit difficult to settle on exact counts, especially as different archetypes will want them to be slightly adjusted and the overall meta has an impact on what players generally find desirable at any given time
Sound the victory fanfare
Then we get to what might be the sweetest slot of all, but also the most swingy