Effect updates and description changes can be seen here.
Shyren is a cheap card with a good ability, making her useful with all soul types. As when placed, she will heal 4 HP to a target of your choice, including enemies and players. This makes Shyren the all-class version of Kindness's Heal (but with 1 more HP and no card draw).
Because of this, Shyren is especially useful in the Kindnessdeck and one should be kept in hand for later in game.
Keep in mind that Shyren's ability will only heal the target, and not increase the Max HP of it, like Force of Nature or Migospel do.