Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip

Trample
Whenever you cast an Aura or Equipment spell, exile the top card of your library. You may play that card until the end of your next turn.

As long as this creature is equipped, it has menace.

, Sacrifice a Goblin: This creature deals 4 damage to target creature.

Whenever you crank Arms Depot, put two +1/+1 counters on target creature.

Creatures target player controls get -2/-2 until end of turn.

: You may put an artifact card from your hand onto the battlefield. That artifact gains haste. Sacrifice it at the beginning of the next end step.

At the beginning of your upkeep, draft a card from Arms Scavenger's spellbook, then exile it. Until end of turn, you may play that card.
Equip abilities you activate cost less to activate.

Arms Scavenger's spellbook includes the following cards:
• Boots of Speed
• Cliffhaven Kitesail
• Colossus Hammer
• Dueling Rapier
• Spare Dagger
• Tormentor's Helm
• Goldvein Pick
• Jousting Lance
• Mask of Immolation
• Mirror Shield
• Relic Axe
• Rogue's Gloves
• Scavenged Blade
• Shield of the Realm
• Ceremonial Knife

, Sacrifice a land: Destroy target land.

Attacking creatures get +2/+0 until end of turn.

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback

Flying, lifelink
Ward — Discard a card.
Whenever a modified creature you control attacks, double the number of each kind of counter on it. Then for each nontoken permanent attached to it, create a token that's a copy of that permanent attached to that creature.

Haste
Boast — : You may change Arni's base power to 1 plus the greatest power among other creatures you control until end of turn. (Activate this ability only if this creature attacked this turn and only once each turn.)

Whenever a creature you control attacks or enters attacking, you may pay . If you do, you may put a creature card with mana value less than that creature's mana value from your hand onto the battlefield tapped and attacking.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
Target creature you control fights up to one target creature you don't control.
Add . Put two +1/+1 counters on up to one target creature you control.
You gain life equal to the greatest power among creatures you control.

, : Create a tapped 2/1 black Villain creature token with menace. Activate only if there are two or more creature cards in your graveyard.

Cumulative upkeep
: Target creature gains flying until end of turn.

Deathtouch
Other Assassins you control get +2/+0.
Disguise

Deathtouch
Whenever a creature you control with power or toughness 1 or less dies, target opponent loses 2 life and you gain 2 life.

Whenever you cast an instant, sorcery, or Wizard spell, Rockslide Sorcerer deals 1 damage to any target.

Menace
, , Sacrifice another creature: Put a +1/+1 counter on each creature you control.

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.

Return target creature to its owner's hand.
Addendum — If you cast this spell during your main phase, draw a card.

Target creature gets +2/+2 until end of turn.
Addendum — If you cast this spell during your main phase, that creature gains flying until end of turn.

Whenever this creature blocks or becomes blocked by a creature with power 1 or less, destroy this creature at end of combat.

When this creature enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.