Having a toolbox of powerful creatures at your disposal gives almost limitless options, and Modern has plenty of tools to offer.
Eldritch Evolution may be the new evolution in making toolboxes work. While you’re not gaining a mana advantage as Evolution itself costs 3 and you can only get a creature with CMC 2 more than what you sacrificed, you can spread that investment out over time and without worrying about color requirements. This means you want a deck full of mana creatures to ramp for value or sacrifice for 3-drops, other creatures that sacrifice for value, and then some payoffs.
Birds of Paradise and Noble Hierarch will get you started. Already great weapons in any creature deck just to make sure you’re on the board early, being able to Evolution on turn 2 to get some of your stellar 3-drops gives you added flexibility. Even better is if you already have those 3-drops in your hand as you now have action on turn 2.
Voice of Resurgence already does a serious number on a handful of decks, especially those relying on countermagic. You’re also getting a reasonably sized 2-drop that sacrifices to Evolution for value and leaves behind a nice monster.
Renegade Rallier can get back your fetchlands to ramp, your mana creatures you sacrificed to Evolution, or anything else small that happened to hit the bin. A turn-1 mana creature into turn-2 Evolution also has the option to go find Eternal Witness. This brings the Evolution back to your hand, ready to find a 5-drop the next turn.
In a similar vein, blinking an Eternal Witness or Renegade Rallier allows you to do some pretty crazy things. Restoration Angel is already a powerhouse in the format as a 3/4 flying creature that dodges Lightning Bolt and Abrupt Decay. When you factor in the infinite combo with Kiki-Jiki that can win on the spot (with Evolutions to help set the whole thing up), Restoration Angel is one of the biggest payoffs for all of these great creatures.
Kitchen Finks is another in the long line of resilient creatures that can be sacrificed for value to Evolution. The life gain here is critical in so many of the matchups that come down to racing.
Huntmaster of the Fells serves a similar purpose in creating an army single-handedly while padding your life total. Huntmaster flipping into a serious threat that can take down creatures, players, and planeswalkers is what made it one of the most powerful cards in Standard for a long time. Resetting these creatures with Restoration Angel puts you crazy far ahead.
This deck only touches blue slightly, but Glen Elendra Archmage is a big payoff. There are a number of decks that simply can’t win without resolving key spells, and Archmage allows you to stay aggressive while threatening to counter those critical spells for a single mana. With Restoration Angel to reset its persist, Kiki-Jiki to set up a loop of counters, and cards like Reveillark and Eternal Witness to bring the Faerie Wizard back, your one Archmage can turn into lots of counters and wins.
Kiki Chord allows us to utilize a powerful toolbox full of options in the Modern format, but required a reasonable board presence (or lots of lands) to actually resolve. Evolution may be the future as you can start going off on turn 2 with revolted Ralliers!