Axgard Cavalry

{T}: Target creature gains haste until end of turn. (It can attack and {T} this turn.)

Arni Brokenbrow

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

Cleaving Reaper

Flying, trample
Pay 3 life: Return Cleaving Reaper from your graveyard to your hand. Activate only if you had an Angel or Berserker enter the battlefield under your control this turn.

Dragonkin Berserker

First strike
Boast abilities you activate cost {1} less to activate for each Dragon you control.
Boast — {4}{R}: Create a 5/5 red Dragon creature token with flying. (Activate only if this creature attacked this turn and only once each turn.)

The Bloodsky Massacre

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/3 red Demon Berserker creature token with menace.
II — Whenever a Berserker attacks this turn, you draw a card and you lose 1 life.
III — Add {R} for each Berserker you control. Until end of turn, you don't lose this mana as steps and phases end.

Frenzied Raider

Whenever you activate a boast ability, put a +1/+1 counter on Frenzied Raider.

Skemfar Avenger

Whenever another nontoken Elf or Berserker you control dies, you draw a card and you lose 1 life.

Duskwielder

Boast — {1}: Target opponent loses 1 life and you gain 1 life. (Activate only if this creature attacked this turn and only once each turn.)

Eradicator Valkyrie

Flying, lifelink, hexproof from planeswalkers
Boast — {1}{B}, Sacrifice a creature: Each opponent sacrifices a creature or planeswalker. (Activate only if this creature attacked this turn and only once each turn.)

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.