Triggered abilities fire automatically when conditions are met
"Lathril's Chant," a favorite tale among the elves, tells of Lathril's birth, deeds, and later ascent to godhood after her battle with a mysterious Cosmos Monster called Eidermaw
Since both of these cards are black, you'll definitely want Inalla, Archmage Ritualist as your commander, but in a deck built around Wizard enters-the-battlefield triggers, you can never have too many Panharmonicon effects, making Naban, Dean of Iteration a great support card in the 99
All walls have defender, but wall refers to a creature type, not the keyword
Some of those big bodies also naturally provide extra value over time, whether its Elfsworn Giant churning out tokens or Cackling Prowler and Needletooth Pack growing your Vampire Gourmand and/or Nighthawk