Finally, its a form of massive card advantage since you can discard the lands for effects like Cathartic Reunion or Seismic Assault
Like most Magic: The Gathering cards, the value of Dragonologist depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Tarkir: Dragonstorm)
Always check your source images before printing
Some of that is just good fortune in how all these effects are worded, but Id say its more that discarding is an inherently effective way to interface with Magic s core mechanics
How PSA Pokmon Card Grading Works
Shinya Mizuno External: Pokemon.com , Bulba #ad / Affiliate Links: TCGplayer , cardmarket , Amazon , eBay The females are fussier than the males