Which traits to roll for "Arms of the Abyss" tentacle grapple?

Question

Page 189 of V20 (core book) describes the Obtenebration ability "Arms of The Abyss" in this manner:

The player spends a blood point and makes a simple (never extended) Manipulation + Occult roll (difficulty 7); each success enables the creation of a single tentacle. Each tentacle is six feet (two meters) long and possesses Strength and Dexterity ratings equal to the invoking vampire’s Obtenebration Trait — Potence and Celerity dots are added to these Strength and Dexterity ratings, respectively. If the vampire chooses, she may spend a blood point either to increase a single tentacle’s Strength or Dexterity by one or to extend its length by another six feet or two meters. Each tentacle has four health levels, is affected by fire and sunlight as if it were a vampire, and soaks bashing and lethal damage using the vampire’s Stamina + Fortitude. Aggravated damage may not be soaked.

What interests me is this part:

Tentacles may constrict foes, inflicting (Strength +1) lethal damage per turn. Breaking the grasp of a tentacle requires the victim to win a resisted Strength roll against the tentacle (difficulty 6 for each). However, tentacles cannot be used for any kind of manipulation, such as typing or driving.

Do I understand it correctly that tentacles don't have to roll Dexterity to actually hit the foe, just STR to check if the grapple attempt is successfully resisted and then an STR roll for damage?

Or do the tentacles roll their Dexterity to check if they hit the foe first?

Thanks in advance.

UPD: adding some more questions from comments.

Do the tentacles contibute to "Multiple Opponents" then, as listed on page 276?

Multiple Opponents: A character who battles multiple opponents in close combat suffers attack and defense difficulties of +1, cumulative, for each opponent after the first (to a maximum of +4).

Can I parry them with a weapon and inflict damage if the parry is successful?

Answer 1

Nothing in the writeup of the ability says that they don't have to grapple the target first as of the standard rules - just that they have a special system to break free from.

This in turn means, that the tentacles can be dodged.

In contrast to Celerity (or a Werewolf's Rage), where one user attacks several times, the tentacles are addional entities. More entities means, that it could count as multiple opponents. A Hint for this is, that they don't need full concentration - which might imply, that they have a live on their one to some degree. However, they don't seem to have their own initiative value.

Update:

The new part about inflicting damage while defending is easily to be solved by looking up defensive actions on page 275 of the core rules (emphasis mine):

There are three types of defensive actions: block, dodge, and parry. [...] Each defensive maneuver uses the same basic system: The defensive action is a resisted roll against the opponent’s attack roll. [... systems explanation here ...]

• Block: A Dexterity + Brawl maneuver using your character’s own body to deflect a hand-to-hand bashing attack. Lethal and aggravated attacks cannot be blocked unless the defender has Fortitude or is wearing armor.

• Dodge: [... irrrelevant to this question ...]

• Parry: A Dexterity + Melee maneuver using a weapon to block a Brawl or Melee attack. If a character makes a Brawl attack and the defender parries with a weapon that normally causes lethal damage, the attacker can actually be hurt by a successful parry. If the defender rolls more successes than the attacker does in the resisted action, the defender rolls the weapon’s base damage plus the parry’s extra successes as a damage dice pool against the attacker.

Blocking is the unarmed defense to bring your arm in between. You want to parry the attacks with a sword. Checking the mentioned page in the core rules (or the bit just above) shows that parrying successfully indeed can inflict damage. Think about it, that if you win a parry, the rules say it would have been as if you attacked in the first place and the tentacle would have failed its defensive action to fully defend itself.

Answer 2

Yes, they do roll to hit first; it's why their Dexterity score is called out in your first paragraph. The role of Arms of the Abyss is to provide extra attacks in a turn to a clan that has no in-clan access to Celerity.