Q2298: If I control two "Bloated, Harahara" and I attack with one "Bloated, Harahara", can I gain +4 life?

A: Yes, you can. [D-Share] can duplicate the same ability.

Q2299: When my "Heavystriker, Kaina" attacked, the D ability of my "Bloated, Harahara" activated. Can I still gain +2 life if my opponent destroys my "Bloated, Harahara" in response?

A: Yes, you can. Even though the card that gave the ability left the field by the time it will resolve, it will still resolve successfully.

Q2301: If I have "Assailant, Tategami" in play, and I call "Bloated, Harahara" successfully, can I drop a soul of an opponent's card?

A: Yes, you can. Cards with [D-Share] get all of the [D] of other cards with [D-Share].

Q2303: Can another card with [D-Share] gain the [D] ability of a "Bloated, Harahara" that is in front of "Sealed Black Crest Dragon, Elgod"?

A: No, you cannot. As the [D-Share] ability is nullified, cards in front of "Sealed Black Crest Dragon, Elgod" cannot pass their own [D] ability to other cards with [D-Share].

Q2304: Can a "Thunderaxe, Agito" that is in front of "Sealed Black Crest Dragon, Elgod" gain the [D] of a "Bloated, Harahara" that you control?

A: Since "Sealed Black Crest Dragon, Elgod" nullifies the abilities, it will also invalidate the abilities the card affected receives as well.