Amazing Alliance

Creatures you control get +1/+1.
Whenever you attack with one or more legendary creatures, you gain that much life.

Spider-Man, Web-Slinger

Web-slinging {W} (You may cast this spell for {W} if you also return a tapped creature you control to its owner's hand.)

Spider-UK

Web-slinging {2}{W} (You may cast this spell for {2}{W} if you also return a tapped creature you control to its owner's hand.)
At the beginning of your end step, if two or more creatures entered the battlefield under your control this turn, you draw a card and gain 2 life.

Amateur Hero

When this creature enters, you gain 2 life.

Plains

Spider-Man, Peter Parker

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever you gain life, put a +1/+1 counter on target creature you control. It gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Friendly Neighborhood

Enchant land
When this Aura enters, create three 1/1 green and white Human Citizen creature tokens.
Enchanted land has "{1}, {T}: Target creature gets +1/+1 until end of turn for each creature you control. Activate only as a sorcery."

Aunt May

Whenever another creature you control enters, you gain 1 life. If it's a Spider, put a +1/+1 counter on it.

Sudden Strike

Destroy target attacking or blocking creature.

Spectacular Tactics

Choose one —
• Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn.
• Destroy target creature with power 4 or greater.

Selfless Police Captain

This creature enters with a +1/+1 counter on it.
When this creature leaves the battlefield, put its +1/+1 counters on target creature you control.

Silver Sable, Mercenary Leader

When Silver Sable enters, put a +1/+1 counter on another target creature.
Whenever Silver Sable attacks, target modified creature you control gains lifelink until end of turn. (Equipment, Auras you control, and counters are modifications.)

MJ, Rising Star

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever you gain life, put a +1/+1 counter on MJ.

Origin of Spider-Man

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/1 green Spider creature token with reach.
II — Put a +1/+1 counter on target creature you control. It becomes a legendary Spider Hero in addition to its other types.
III — Target creature you control gains double strike until end of turn.

Rent Is Due

At the beginning of your end step, you may tap two untapped creatures and/or Treasures you control. If you do, draw a card. Otherwise, sacrifice this enchantment.

Reprieve

Return target spell to its owner's hand.
Draw a card.

Thwip!

Target creature gets +2/+2 and gains flying until end of turn. If it's a Spider, you gain 2 life.

Web Up

When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Bagel and Schmear

Share — {W}, {T}, Sacrifice this artifact: Put a +1/+1 counter on up to one target creature. Draw a card. Activate only as a sorcery.
Nosh — {2}, {T}, Sacrifice this artifact: You gain 3 life and draw a card.