nightmist question

So, in the game and video game, I kept seeing and hearing that nightmist can draw 3 cards when she has mist form out, even though she can't use her power. How?

When you skip power and play phases you draw an extra card.  That is in addition to the card draw Mistform gives you.  

Same thing works with Visionary’s Cocoon and Bunker’s Recharge Mode, if you’re looking for other tactics.

I don't think TK Coccoon lets you draw an extra card. Recharge Mode definitely does, though. So yeah, the first turn you use Mist Form/Recharge Mode, you would just get to draw two cards (since you used your card play to put that card out in the first place) but on subsequent turns if you're not playing a card or using powers (which those cards tend to prevent you from doing anyway) you get to draw your normal two cards for skipping those phases, plus the extra one the form card lets you have :).

Note that if Nightmist has her medallion in play before playing Mist Form, she can stil discard at the end of her turn to heal. Nothing about Mist Form prevents that. This is usually huge because it permits Nightmist to heal up before returning to normal form and re-entering the fight.