It is a threat in its own right and it is a combo piece but also just a very good card
(6/14/2019) The copy has the same value of X
Theyre action at a cost, and you start getting into logjams where you cast your learn card, then cast the Lesson, then draw more learn cards in the process, and have more spells than you have mana to cast them
The supply is limited and that means that, as Magic grows, demand will only grow for these cards (especially since people know they won't be printed again)
If it features Pokemon species the Pokemon cards on the back will be Fire Energy, Charmander, Rattata, a back image of a card, Potion, Machop, and a Fighting Energy the art with only energy cards shows one Pokemon card back and Grass, Fire, Water, Lightning, Psychic, and Fighting energy cards

Awaken the Maelstrom Baleful Mastery Black Widow, Agile Avenger Booby Trap Consecrated Sphinx Defacing Duskmage Faerie Mastermind Fate Unraveler Infernal Offering Kederekt Parasite Leela, Sevateem Warrior Malignant Growth Mathas, Fiend Seeker Mind's Eye Mind's Eye Nekusar, the Mindrazer Norn's Decree North Pole Research Base Notion Thief Ob Nixilis Reignited Ob Nixilis, the Hate-Twisted Orcish Bowmasters Pendant of Prosperity Razorkin Needlehead Red Death, Shipwrecker Saltwater Stalwart Sapphire Charm Sazacap's Brew Scrawling Crawler Sheoldred, the Apocalypse Smothering Tithe Tataru Taru The Unagi of Kyoshi Island Thief of Existence Trouble in Pairs Underworld Dreams Wedding Ring Xyris, the Writhing Storm Zurzoth, Chaos Rider