"Two pile" cards will always have a barrier to entry, I feel. It's just a hard operation to complete successfully. My top two contenders are probably:Anyone got any lower power alternatives for Fact or Fiction? Preferably also at instant speed?
While I personally love Fact or Fiction, it's a little bonkers for in a format with a relatively constrained power level. It's also super punishing to newer players: while veterans of the game like ourselves have a lot of fun with it, and are attracted to super Spike-y cards like this, my observation is that players with less experience are handing the game to their opponent as they make their two piles, without really understanding or realizing the ramifications of what they've just done.
Also:
Not really a big fan of FOF either: it tends to slot too well into the those blue jund style decks, and control has a hard enough time as is in these midrange formats.
Grabbing Starstorm is a horrendous idea, since you get to cast the spell for X = 0 sigh's suggestions are wonderful though. It also interacts hilariously with split cards, allowing you to cast either half, even if the side that's red or white had a cmc > 4 and the side that has a cmc <= 4 isn't red or whiteI also haven't fully thought out all of the possible cards it could grab, but I rather like: