TL;DR: Enchanted cards are alternate-art, borderless, inkwash foil versions of existing Lorcana cards
For example, getting Elspeth Conquers Deaths Chapter I during your draw step every turn, or Tale of Tinuviels chapter II every turn is going to overwhelm your opponents in a hurry
There will also be a format known as Infinity Constructed, and all cards, regardless of legality, may be used in that format
These will always detail how and when you use them, although it should be noted that many abilities for lower level characters will often exert the card which is symbolised with a small icon indicating a turning arrow
Now if Tamatoa Happy as a Clam remains in play and you can Quest with it, then you can cheat out an item card on the board without having to use any Ink
The Willpower buff alone could make this card see some play in Sapphire decks, and the extra Lore plays perfectly into how the Support mechanic works