Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Kavu Glider

{W}: Kavu Glider gets +0/+1 until end of turn.
{U}: Kavu Glider gains flying until end of turn.

Alpha Kavu

{1}{G}: Target Kavu creature gets -1/+1 until end of turn.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Sparkcaster

When Sparkcaster enters, return a red or green creature you control to its owner's hand.
When Sparkcaster enters, it deals 1 damage to target player or planeswalker.

Caldera Kavu

{1}{B}: Caldera Kavu gets +1/+1 until end of turn.
{G}: Caldera Kavu becomes the color of your choice until end of turn.

Jared Carthalion

+1: Create a 3/3 Kavu creature token with trample that's all colors.
−3: Choose up to two target creatures. For each of them, put a number of +1/+1 counters on it equal to the number of colors it is.
−6: Return target multicolored card from your graveyard to your hand. If that card was all colors, draw a card and create two Treasure tokens.
Jared Carthalion can be your commander.

Ancient Kavu

{2}: Ancient Kavu becomes colorless until end of turn.

Kavu Howler

When Kavu Howler enters, reveal the top four cards of your library. Put all Kavu cards revealed this way into your hand and the rest on the bottom of your library in any order.

Amphibious Kavu

Whenever Amphibious Kavu blocks or becomes blocked by one or more blue and/or black creatures, Amphibious Kavu gets +3/+3 until end of turn.

Firemaw Kavu

Echo {5}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Firemaw Kavu enters, it deals 2 damage to target creature.
When Firemaw Kavu leaves the battlefield, it deals 4 damage to target creature.

Sol Ring

Flametongue Kavu

When Flametongue Kavu enters, it deals 4 damage to target creature.

Hooded Kavu

{B}: Hooded Kavu gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Horned Kavu

When Horned Kavu enters, return a red or green creature you control to its owner's hand.

Firescreamer

{R}: Firescreamer gets +1/+0 until end of turn.

Flowstone Kavu

Menace (This creature can't be blocked except by two or more creatures.)
{R}: Flowstone Kavu gets +1/-1 until end of turn.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Defiler of Instinct

First strike
As an additional cost to cast red permanent spells, you may pay 2 life. Those spells cost {R} less to cast if you paid life this way. This effect reduces only the amount of red mana you pay.
Whenever you cast a red permanent spell, Defiler of Instinct deals 1 damage to any target.

Thunderscape Familiar

First strike
Black spells and green spells you cast cost {1} less to cast.

Hunting Kavu

{1}{R}{G}, {T}: Exile Hunting Kavu and target creature without flying that's attacking you.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Kavu Aggressor

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Kavu Aggressor can't block.
If Kavu Aggressor was kicked, it enters with a +1/+1 counter on it.

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.