Mythic rares tend to show up at lower-than-expected rates in most Collector Boosters, so they often hold their value pretty well regardless of how much Constructed play they see
Like most Magic: The Gathering cards, the value of Emry, Lurker of the Loch 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 (Throne of Eldraine Promos)
Players can acquire two Lore points by questing with this card too
For non-creature reprints, Im struck by the all-star team of enchantments picked out to enhance our amphibious assault: Deeproot Waters, Reflections of Littjara, Hardened Scales, Simic Ascendancy, Kindred Discovery and Branching Evolution