I haven't really kept up with 5e much. I went from 4e to 13th Age, and am QUITE satisfied. Incidentally, the sorcerers and necromancers in 13th Age has a similar ability, but it just augments existing spells and is open to GM interpretation, so while it might not be as POWERFUL, it's certainly always interesting.
Gather Power (Sorc version): Once initiative has been rolled and a battle is underway, a sorcerer can spend a standard action to gather magical power, preparing themselves for casting a double-strength spell with their next standard action. Gathering power is loud and very noticeable. In addition, because you spend your standard action to gather power, you generate a small magical benefit. Like many of your powers, this benefit is chaotic rather than perfectly reliable, so you must make a random check to see what benefit you get. Roll a d6 and consult the appropriate table below. If you get a benefit that deals damage to enemies, you can choose the type of damage (cold, fire, lightning, or thunder).
Cackling Soliloquist (Necro version): If you spend your move action, your quick action, and your standard action casting a daily spell that ordinarily only requires a standard action—while screaming grandiloquently, cackling maniacally, or megalomaniacally describing the grandeur of your plans and the futility of your enemies’ resistance—the daily spell is recharge 18+ after battle instead of daily, and you can invent a slight improvement to the spell, especially if it’s partly story-oriented, that provides an extra benefit determined by the GM or by you (with GM approval).