Activate Terra, Magical Adept by paying 4 and tapping it, causing you to exile it and return it to the battlefield as Esper Terra.
As Esper Terra enters the battlefield, choose to have it enter with four lore counters due to its read-ahead ability.
Esper Terra's fourth chapter ability triggers, causing you to add , and then exile Esper Terra and return it to the battlefield as Terra, Magical Adept.
When Terra, Magical Adept enters the battlefield, it triggers, causing you to mill five cards and put up to one enchantment card milled this way into your hand.
Repeat.
This magnificent loop harnesses the power of transformation by leveraging Barbara Wright: History Teacher, whose read-ahead ability allows Esper Terra to instantly bypass its early chapters and enter directly with four lore counters. The moment Esper Terra hits chapter IV, it showers you with ten colored mana and resets itself back into Terra, Magical Adept, whose enter-the-battlefield trigger mills your library while retrieving an enchantment. Thanks to Gimli's Reckless Might, any supporting permanents or creatures you manage to assemble along the way gain haste, turning this self-sustaining engine into an infinite well of mana, creature triggers, and self-mill.