Black Luster Soldier – Envoy of the Beginning

After six whole years of being banned, Black Luster Soldier – Envoy
of the Beginning has returned once again to the latest format. Having
single-handedly defined the last few formats while he was still limited,
it is without a doubt that Black Luster Soldier – Envoy of the
Beginning will make a dominating presence in the new format.

There is no better timing for newer players to get acquainted and older players to get reacquainted with his latest rulings.



Yu-Gi-Oh! OCG Rules & FAQ Official Database (Japanese)

●フィールド上のモンスターを除外する効果は、自分のターンのメインフェイズに発動する効果となります。
●もう1度攻撃できる効果は、ダメージステップにて発動し、チェーンブロックが作られる効果となります。
●除外されるカードは、表側表示で除外されます。

• The effect to banish a monster on the field, can only be activated during the Main Phase of your own Turn.
  
• The effect to attack once again in a row, activates during the Damage Step, creating a Chain Block for the effect.
  
• Cards that are banished, are banished face-up.
  

Source: 遊戯王OCG ルール＆ＦＡＱ 公式データベース （日本語版）

Yu-Gi-Oh! Card Wiki

Ｑ：効果分類は何ですか？
Ａ：フィールド上に存在するモンスター１体をゲームから除外する効果は起動効果で、戦闘によって相手モンスターを破壊した際に、もう一度攻撃する事ができる効果の種別は、誘発効果です。
　　なお、もう一度攻撃する事ができる効果の発動するタイミングは、ダメージステップ中となり、メインフェイズにて効果を発動する事を宣言する必要はありません。(11/08/18)

Q: How are the effects classified?
A: The effect “Select 1 monster on the field, and banish it from play”
is an Ignition Effect, the effect “If this card destroyed your
opponent’s monster by battle, it can attack once again in a row” is a
Trigger Effect.
Furthermore, the timing to activate the effect of attacking once again
in a row, is during the Damage Step, it is not required to declare the
activation of this effect during the Main Phase. (18th August 2011)

Source: 《カオス・ソルジャー －開闢の使者－》 -遊戯王カードWiki

Conclusion
Unlike Chaos Sorcerer that can banish only face-up monsters, Black
Luster Soldier – Envoy of the Beginning can banish both face-up and
face-down monsters, and the monster will always be banished face-up.

Back in 2005 while Black Luster Soldier – Envoy of the Beginning was
still limited, it was ruled that the player had to declare that he was
activating the effect of attacking once again in a row during the Main
Phase. This ruling has been revised and the latest ruling do not require
the player to declare the activation of that effect during the Main
Phase.

Additionally, after the effect of attacking once again in a row has
resolved successfully during the Damage Step, the additional attack has
to be performed on the immediate next Battle Step. That is to say the
second attack has to be performed right after the first attack. If the
player declared an attack with another monster after Black Luster
Soldier – Envoy of the Beginning’s first attack, then Black Luster
Soldier – Envoy of the Beginning would had missed his chance to perform
his second attack.