You can only activate the "when this card is trashed from the deck" when this card is directly trashed from the deck.
Festival in a Box nets you a mountain of the special merch and collectors items you would find at the show
Promo Info BOOSTER EXCEED APOCALYPSE [BT-15] CLOSECLOSE BT15-059 C Digimon Lv.4 Airdramon Color Black Form Champion Attribute Vaccine Type Mythical Beast/SoC DP 4000 Cost 5 Digivolve Cost 1 2 from Lv.3 Digivolve Cost 2 - Upper Text [Digivolve] Lv.3 w/[SoC] trait: Cost 2 [On Play] [When Digivolving] By placing 1 [Marvin Jackson] from your hand as this Digimon's bottom digivolution card, De-Digivolve 1 1 of your opponent's Digimon
The Autumn set will feature the debut of Legendaries Kyurem and Giratina as VSTAR cards, and will also bring back the "Lost Zone" Pokmon Trading Card Game mechanic which hasn't been seen since 2018.
Drownyard Temple is a free source of colorless mana that can be rebought in late-game situations or as an on-curve way to accelerate into Reality Smasher or Chandra, Flamecaller
The website has a dedicated article page, which is searchable by year, detailing all sorts of interesting information relating to Pokmon's past
