Despite its steep 6-mana casting cost, The Eighth Doctor functions as a stronger Emry, Lurker of the Loch that can still participate in combat with its 4/4 body
It also eventually represents a later threat of Chalice on two, making the combo very hard to assemble, meaning multiple Chalices are good even if that decks best answer is the three-cost Teferi, Time Raveler
The mana-preserving ability lets you ramp out huge Eldrazi titans as early as turns 5-6, and thats something that other players usually arent ready to deal with so early
Illustrated by Rob Alexander Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
1 - Sylvan Tutor Green decks already have powerful tutors with Chord of Calling, Archdruid's Charm and even Natural Order to cheat on mana costs, and now, Sylvan Tutor joins this wide range to search for any creature for just one mana