Ongoing discussion of cards that should be considered in Modern.
My contention: 1 copy of sultai should be mainboarded when possible.
Advantages:
-diverse options basically guarantee usability
-relatively low cost
Disadvantages:
-triple color makes it harder to play/use
-unusual color combo
-slightly limited creature control
Why I think it should be mainboarded:
1- its good to draw in almost any situation- for 3 mana, at instant speed, you either destroy a threat or gain tactical advantage. Yes, the creature removal is limited because it "destroys" and can only target monocolored, but that's quite a few good matchups covered (goyf, bob, hierarch, etc) as well as the general idea of creature removal covered, and, if it can't snap out a creature, you have other options. Mainboarded artifact or enchantment destruction is wonderful game 1 as it handles threats in tron, targets pretty much everything in affinity, and handles lots of sticky removal options like o-ring, pithing needle, etc. And, best of all, if for some reason you're playing against a deck that runs few to no creatures or few to no artifacts or enchantments, OR if you have drawn a bad hand early and need to regain tempo, you can just wait till the end of opponent's turn and draw 2 and discard 1, rearranging itself and your hand to gain advantage. So, unless opponent can stop you from everything you want to do in magic, this card is basically never a bad draw.
2- good at any mana level or time in the game- since it only costs 3 and is an instant, its my contention that sultai charm is good in the opening hand, in the middle game, and as a top deck, making it at least a decision in any deck that can run the color scheme. The creature removal early, the late game options on removal of pretty much everything, and the age old top deck into draw 2 discard 1 for a low cost that lets you play the card you draw is too good not to consider.
Arguments against mainboarding and relevance in modern in general:
1- bad color combo- yes, its an unusual color combo, but in my opinion not a bad one. I've had plenty of success with sultai colors in modern, as blue gives control and tactical advantage, black gives arguably whatever you need, and green gives a little muscle as well as a surprising amount of card advantage in combo with blue and black.
2- tri color makes it harder to play- its true, anything that costs 3 colors brings down the playability just based on difficulty of assembling the 3 colors, but with all the fetch lands and split lands, it's honestly not hard to get this card in motion, even with only 3 lands in play.
3- three mana for a spotty removal is a waste of mana- true, you could always path, terminate, fatal push, lightning bolt your way around creatures for less mana, and the monocolored restraint hurts when you see a dropped threat that runs a split, but the sheer versatility of this card's control options outweigh the limits it has on mana to removal output. The card basically reads- either handle a threat or rearrange your hand so you have a way to handle a threat.
Conclusion: sultai charm is worth consideration for any deck that can run its colors. However, I wouldn't recommend more than a splash of this card, simply because it does cost 3, at 3 colors, and more efficient/potent creature removal exists in these colors anyway. That being said, I have yet to draw this card and think- damnit.