At the beginning of your end step, each player mills two cards. Then if it's your first turn of the game or you discarded a card named Leystone of Ruin this turn, target opponent mills four cards.
Cycling {B}

At the beginning of your end step, Leystone of Storms deals 1 damage to each opponent. Then if it's your first turn of the game or you discarded a card named Leystone of Storms this turn, Leystone of Storms deals 1 damage to any target.
Cycling {R}

Whenever you cast an instant spell, up to one target creature gets +2/+2 until end of turn.
Whenever you cast a sorcery spell, reveal the top card of your library. If its mana value is less than the greatest power among creatures you control, put it into your hand.

Equipped creature gets +2/-1.
Equip {1}

{T}: Add {R}{R}{R}. Spend this mana only to cast creature spells. If that mana is spent on a creature spell, it enters with an additional haste counter and decayed counter on it.

{5}: Lightspeed Cruiser becomes an artifact creature until end of turn.
Crew 2

Attacking creatures you control have first strike.
Whenever you amp it up, draw a card.

Enchant land
When Lightvein Discovery enters, put a +1/+1 counter on target creature you control.
Enchanted land has “{T}: Add two mana of different colors.”

{T}: Target land you control becomes a 4/4 Elemental creature with lifelink, haste, and “When this creature dies, draw a card.” It's still a land. Sacrifice it at the beginning of the next end step.

Menace
Other Elementals you control have menace.

Whenever Lithe Stalker or another artifact you control enters, artifact creatures you control gain first strike until end of turn.

{1}, {T}: Add one mana of any color.
{2}, Sacrifice Living Compass: Draw a card.

Enchant creature
Enchanted creature gets +2/+2.
Wander {2}{W}

Flying
When Lofty Voter enters, make a pledge.

Solidarity
Londel Sharpshot can't be blocked by creatures with power 2 or less.

Whenever this creature transforms into Lone Switchblade or another permanent you control transforms, each opponent loses 1 life and you gain 1 life.

Flash
Flying, lifelink
Your opponents can't create tokens.

Looming Skyscrapers enters tapped.
{T}: Add {B} or {G}.
{4}: Make a pledge. Activate only as a sorcery.

Menace
{B}{R}: Target creature with power 4 or less can't be blocked by more than one creature this turn.

Kraken, Leviathan, Octopus, and Serpent spells you cast cost {X} less to cast, where X is your devotion to blue.

When Lost Resistor dies, you gain 1 life.
Cybersoul {X}{X}{W}

Before equipped creature would assign, deal, or be dealt damage, sacrifice Lum Berry. If you do, equipped creature gets +1/+1 until end of turn.
When you sacrifice Lum Berry, you may exile equipped creature, then return that card to the battlefield under its owner's control. Put a +1/+1 counter on it.
Equip {1}

Lunar Plateau enters tapped.
{T}: Add {W} or {B}.
{1}, Discard Lunar Plateau: Scry 2.

Menace
Drop — Lurking Glitch enters with two +1/+1 counters on it if you didn't cast any creature spells during your last turn.

Whenever Lurking Vyrkolakas attacks, exile target card from a graveyard. If a nonland card was exiled this way, put a +1/+1 counter on this creature. If a land card was exiled this way, this creature gains lifelink until end of turn.