You may play Grisly Ruins from your graveyard as long as seven or more cards are in your graveyard. Grisly Ruins enters tapped. {T}: Add {B} or {G}. Cycling {1}{B}{G}({1}{B}{G}, Discard this card: Draw a card.)
Grizzled Den enters tapped. {T}: Add {R} or {G}. {3}{R}{G}: Until end of turn, Grizzled Den becomes a Bear creature with trample in addition to its other types. Scavenge {4}{R}{G}
Guang Shrine enters tapped. {T}: Add {G} or {W}. {G/W}, {T}, Sacrifice Guang Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.
Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.) {1}, Sacrifice two Clues: Unlock Hall of Lost Histories and put the revealed card into your hand.
Flying At the beginning of your first main phase, you may put any number of land cards from your hand onto the battlefield, then draw a card for each land put onto the battlefield this way.
{T}: Add {C}. {T}, Reappropriate: Add {U} or {R}. (Exile exactly two cards from your hand and/or graveyard.)
“At night, the dead revel in the halls of the living. Join them with caution; though their tables are plentiful and their gifts generous, they will see you come back for more.” —Vakavanha, Who Sees Anew
Hazy Coppice enters tapped. {T}: Add {U} or {B}. {2}{U}{B}: Until end of turn, Hazy Coppice becomes a 4/4 blue and black Bird creature with with flying and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)