A Killer Among Us Adaptive Automaton An Unexpected Party An-Zerrin Ruins And They Shall Know No Fear Arachne, Psionic Weaver Arcane Adaptation Ashes of the Fallen Banner of Kinship Barbarian Guides Belbe's Portal Black Market Connections Blood Oath Bloodline Bidding Bloodline Pretender Bloodline Shaman Brass Herald Caller of the Hunt Callous Oppressor Cavern of Souls Celestial Reunion Chronicle of Victory Circle of Solace Coalition Flag Collective Inferno Conspiracy Coordinated Barrage Cover of Darkness Crippling Fear Deification Distant Melody Doom Cannon Door of Destinies Elvish Soultiller Engineered Plague Etchings of the Chosen Fertile Imagination For the Ancestors From the Rubble Gathering Stone Gauntlets of Chaos Giant Slug Harmonized Crescendo Haunting Voyage Herald's Horn Icon of Ancestry Illusionary Presence Imagecrafter Instruments of War Juxtapose Kindred Boon Kindred Charge Kindred Discovery Kindred Dominance Kindred Summons Leyline of Transformation Lifecraft Engine Littjara Luminescent Rain March from Velis Vel Metallic Mimic Mirror Entity Avatar Mirror of the Forebears Mistform Mutant Mistform Wakecaster Molten Echoes Morophon, the Boundless Obelisk of Urd Oko, Shadowmoor Scion Orcrist, Goblin-cleaver Outbreak

Further to this having haste without the need to sacrifice a dork more than makes up for the one power difference
If you have any engine that triggers whenever a card leaves the graveyard (Insidious Roots), or a prowess card, Lluwen can power that up, while it makes sacrifice fodder for more death triggers
Lore is typically acquired by sending the characters you have in play on quests (there are also other methods), but we are getting ahead of ourselves
A prominent example is the "Voltron" strategy, when the deck casts its commander and loads it up with powerful equipment and aura cards to create an unstoppable attacker
This should be a sideboard 2-of in decks from Pioneer to Vintage