Rafiq of the Many

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, it gains double strike until end of turn.

Forest

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Cathedral of War

Cathedral of War enters tapped.
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {C}.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Ancient Ziggurat

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Finest Hour

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, if it's the first combat phase of the turn, untap that creature. After this phase, there is an additional combat phase.

Giltspire Avenger

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Destroy target creature that dealt damage to you this turn.

Aven Squire

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Island

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Plains

Sublime Archangel

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Other creatures you control have exalted. (If a creature has multiple instances of exalted, each triggers separately.)

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Angelic Exaltation

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

Flight

Enchant creature
Enchanted creature has flying.

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Akrasan Squire

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)