Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Indomitable Might

Flash
Enchant creature
Enchanted creature gets +3/+3.
Enchanted creature's controller may have it assign its combat damage as though it weren't blocked.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Prodigious Growth

Enchant creature
Enchanted creature gets +7/+7 and has trample.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Demonic Embrace

Enchant creature
Enchanted creature gets +3/+1, has flying, and is a Demon in addition to its other types.
You may cast Demonic Embrace from your graveyard by paying 3 life and discarding a card in addition to paying its other costs.

O-Naginata

O-Naginata can be attached only to a creature with power 3 or greater.
Equipped creature gets +3/+0 and has trample.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Raised by Giants

Commander creatures you own have base power and toughness 10/10 and are Giants in addition to their other types.

Sarevok, Deathbringer

At the beginning of each player's end step, if no permanents left the battlefield this turn, that player loses X life, where X is Sarevok's power.
Choose a Background (You can have a Background as a second commander.)

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Cartouche of Ambition

Enchant creature you control
When Cartouche of Ambition enters, you may put a -1/-1 counter on target creature.
Enchanted creature gets +1/+1 and has lifelink.

Guardian Augmenter

Flash
Commander creatures you control get +2/+2.
Commanders you control have hexproof.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Eldrazi Conscription

Enchant creature
Enchanted creature gets +10/+10 and has trample and annihilator 2. (Whenever it attacks, defending player sacrifices two permanents of their choice.)

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Ancestral Mask

Enchant creature
Enchanted creature gets +2/+2 for each other enchantment on the battlefield.