Ok so I have a Black Templar Assault Marine wielding two Chain Swords, I have Swift attack and the Holy Vengeance Squad ability.

A Hive Tyrant Showed its ugly face so I assaulted it, my initiative was higher than his so I went first.

According to swift attack I have two attacks with my main hand and one attack with my off-hand. Holy Vengeance says follow up an attack with another attack.

I made my first three attacks all of which were successful, so I followed those up with three more attacks. Having a very high WS I landed hits will all six of my attacks.

The Tyrant failed to dodge.

I then moved onto damage 1d10+15 is my damage roll, rolling the 1d10 twice taking the better of the two rolls, with Pen 4 on the sword anything over 21 was damage done. On four of the six damage rolls “tens” were rolled enacting Fury of the Emperor, several times. So by the end more than 120damage was done, thus slaying the Tyrant in one round of attacks.

Question) When rolling the extra 1d10 damage, do I get to roll it twice taking the better of the two for the chain sword (we went with yes)
Thanks

No, you didn't play it correctly.

Holy Vengeance only works when making a Standard Attack (page 242). It cannot be used with Multiple Attacks (page 241). If this Standard Attack hits, you may repeat the attack. You may continue this process until you miss or until you've made a total number of Standard Attacks equal to your Agility Bonus +1 (the "+1" is the initial attack).

Also, the extra d10 rolled for damage with Righteous Fury does not benefit from Tearing.

Ok thanks for clearing that up. End result would have been similar (agi bonus 5) so I still would have hit 6 times, but damage would have been lower.

Thanks again.

Valdyr said:

This actually sounds pretty dangerous. If you rolled highest initiative and charged the hive tyrant, you only get one attack with that charge. You can't do a Swift Attack or activate Holy Vengeance until your next turn. And between the charge and your next turn, a Hive Tyrant get 4 very heavy hitting attacks on you.

To me it sounds like your group played out this scenario rather incorrectly, and it would probably have had another outcome in most other groups.

Valdyr said:

Swift attack only gives you two attacks as a full action. You do not get another attack with your off-hand unless you also have two-weapon weilder (which would give all your attacks a -10 to hit if you use the extra attack from that talent).

herichimo said:

To add to this, attacking with the second hand is also a full round attack. So for example if you do not have swift attack but do have two weapon wielder, to attack with both is a full attack. It just so happens the talents stack together, meaning if you have both you can then use swift attack and your off hand on, as Herichimo says, a full round action.

Preternatural Speed
Prerequisites: Weapon Skill 40, Agility 50
The character is a swift moving bringer of death, a living,
bloody scythe before whom foes die like corn before the
reaper. The character may use Swift Attack and Lighting
Attack as a Half Action rather than a Full Action. In addition,
the character may use the Swift Attack and Lightning Attack
Talents during a Charge.

about 1500 or 2k xp i think

Squad Attack Pattern, only BT marines benefits from it unless your a tactical with Tactical Expertise, listed below Holy Vengeance. I believe theres a talent or something you can purchase to make it apply to your team that isn't tactical only not sure though.

Holy Vengeance
Chapter: Black Templars
Action: Half Action
Cohesion Cost: 2
Sustained: No
Effects: The holy fury of the Emperor lives in the hearts of all
Black Templars, awaiting the time when it will be unleashed
upon his foes. Until the start of his next Turn, whenever the
Battle-Brother and those in Support Range of him make a
successful Standard Attack with a melee weapon (whether
or not Damage is inflicted) they may immediately make an
additional Standard Attack with that same weapon, against
the same foe, as a Free Action. If this blow also hits, then they
may make an additional Standard Attack and so on, up to a
total number of extra attacks equal to their Agility Bonus.
Improvement: If the Battle-Brother is Rank 4 or more,
summoning the Holy Vengeance is a Free Action.

tactical expertise
When initiating a Squad Mode ability, the Tactical Marine
may share the benefits of his Chapter’s Squad Mode
abilities with the members of his Kill-team as if they were
part of his Chapter. This requires a successful Hard (-20)
Command Test. At Rank 3, the Command Test becomes
Challenging (+0). At Rank 7, the Command Test becomes
Routine (+20).

It has long been clarified through email that you don't need TWW to be able to use two weapons. If you want to know how it works in detail in DW; have a look at the DH errata.

Alex