Crown of Empires

{3}, {T}: Tap target creature. Gain control of that creature instead if you control artifacts named Scepter of Empires and Throne of Empires.

Archelos, Lagoon Mystic

As long as Archelos is tapped, other permanents enter tapped.
As long as Archelos is untapped, other permanents enter untapped.

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Puppet Strings

{2}, {T}: You may tap or untap target creature.

False Floor

This artifact enters tapped.
Creatures enter tapped.
{2}, {T}, Exile this artifact: Exile all untapped creatures. Activate only as a sorcery.

Grimgrin, Corpse-Born

Grimgrin enters tapped and doesn't untap during your untap step.
Sacrifice another creature: Untap Grimgrin and put a +1/+1 counter on it.
Whenever Grimgrin attacks, destroy target creature defending player controls, then put a +1/+1 counter on Grimgrin.

Hylda's Crown of Winter

{1}, {T}: Tap target creature. This ability costs {1} less to activate during your turn.
{3}, Sacrifice Hylda's Crown of Winter: Draw a card for each tapped creature your opponents control.

Baloth Prime

This creature enters tapped with six stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you sacrifice a land, create a tapped 4/4 green Beast creature token and untap this creature.
{4}, Sacrifice a land: You gain 2 life.