It will trigger a maximum of once per turn, no matter how many opponents have lost 2 or more life
BT5-103 U Option A Blazing Storm of Metal
Sometimes, though, White has a couple options that can hit both artifacts and enchantments as well, such as Loran of the Third Path or Rambunctious Mutt, but they're far less universal by way of comparison
In case you're wondering how long will it take you to complete the first set of cards, you first need to spend $1,500
Special Summon this card from your hand or GY in Defense Position, then you can [Additional Effect]." The two key "Drytron" monsters are "Alpha Thuban" and "Zeta Aldibah", which search a Ritual Monster and Spell when Special Summoned by their own effects, respectively