Today marks the beginning of prerelease events for Magic: The Gathering's newest set, Theros: Beyond Death. Events are apt to begin sometime this afternoon at the very earliest and continue into Sunday.
At the Theros: Beyond Death prerelease event, players will be handed a prerelease pack: six booster packs of the new set, a date-stamped rare or mythic rare card, and a spindown die. Players will then craft decks consisting of 40 or more cards from the packs (basic lands will be provided and are included in that 40-plus-card figure, as is the date-stamped card), and then proceed to use these newly-made decks in a Limited Sealed event against the other players. Prize support typically follows for good standings!
Now then, I predict that two-color decks will be better than decks with more than that in this meta. However, this is only true unless the cards with the Devotion mechanic are so good in a specific color for a player that that player feels compelled enough to make a one-color deck. In a Limited environment, I do not see this happening often, so, from one player to a good many others, I implore you to reconsider mono-color decks in this Sealed environment unless you have absolutely one hundred percent confidence in that color and nothing better has come along for it. Splashes of a second color might be okay too – just be aware of your color ratios when building your Sealed deck.
I also want to stress that while graveyard hate is rampant in this metagame, it is less likely to emerge in this environment which means the Escape mechanic is going to flourish, especially the longer the game continues. There are a fair few creatures in this set that just won't die, which means removal will be paramount to getting any sort of pot-shot in at an opponent but will only go so far.
If you're worried, know that there will most certainly be players at your local gaming store who are more than willing to help you craft a great Sealed deck at this and every prerelease event. This sort of event is casual and meant to be a fun learning experience for everyone involved. So let's keep that in mind while we enjoy the Theros: Beyond Death prerelease!