You can certainly "Encourage" life loss by attacking
Oh, and when it comes to defenders buying you time to build up to when you can establish dominance via combo or control, nothing is better than these guys because they give you a card to keep digging to find that needed mana, combo piece, or removal
As for how they play, each Final Fantasy Commander Deck has a unique construction and style that encourages a different style of play
The most valuable cards from the XY set typically include holographic rare cards, first edition prints, and cards featuring popular Pokemon
I think the intention here was to fly through the TCGs 30-year history, given the cards appeared in chronological order, beginning with that classic Chonkachu #58 and the infamous holo Charizard from the Base Set (although here shown as Glurak, its German name), before jumping to a French Palkia Lv