Players cant gain life
You play a land, you draw a card (which is often another land), you play that land as your bonus drop, and you draw another card
Howling Mine Howling Mine (and similar iterations like Dictate of Kruphix or Kami of the Crescent Moon) is central to whats known at Commander tables as group hug. In Commander lingo, thats cards that provide a benefit to one or several of your opponents
Cryptic: Trazyn is known as a great collector of spectacular wonders (and occasionally individuals) from across the gallery, and his ability pays some homage to it
Pokmon-V reward players with two prize cards for knocking them out, but they can also level up into Pokmon-VSTAR or -VMAX, the latter of which rewards three prize cards
Inventors Card Image Gallery to see all the templating, art, and rules changes that have been implemented in that set