[Spirit host....who uses them?]

 

On 5/14/2018 at 6:28 PM, AverageBoss said:

Only if you can counter that with a +1 of your own. Otherwise, those 6s you roll become 5s.

Those 6s are still mortal wounds as it's an unmodified 6 are mortals before any modify is applied 

[How does roll of 6 always succeed work?]

On 3/23/2018 at 8:26 AM, RuneBrush said:

It wouldn't as the Rule of One simply states that a roll of 1 fails, it's an immediate action so you couldn't proceed onto applying modifiers. 

In essence you're right, for rolls of 1 and 6, the modifiers almost don't matter - however the one thing to bear in mind, is that even though you may always hit/wound on a 6, abilities might not trigger.  In the Neferata example, if the attacker were a unit of Spirit Hosts (5+ to hit and causing a Mortal Wound on a roll of 6+), the Spirit Hosts would never be able to cause a mortal wound.

Sadly not, because a roll of 6 being successful only applies to To Hit and To Wound rolls, not Save rolls.  If something hits your blood reavers with -1 rend it will still shred them into offerings for Khorne

Mystic shield (or any + save ability) will confer onto the re-roll too.  The "before modifiers" part of re-rolling really only applies if you have a "re-roll failed X".  Best way to show this is another example

A single Skull Reapers is attacking Neferata, once again she's fired off her command ability and that pesky Necromancer has put Overwhelming Dread on them, putting him at -2 to hit.  The Skull Reaper has gained the ability to Re-roll all failed Hit rolls, and this turn makes a whopping 5 attacks with his Daemonblades (4+ to hit).  He makes his to hit-rolls: 1, 3, 4, 5, 6.  He can choose to re-roll the 1 and 3 as before modifiers they failed to hit.  The 4 and 5 cannot re-rolled as they would be a success (again before modifiers).  He re-rolls two dice and gets a 1 and a 6.  He now applies his modifiers and the two 6's become 4's, which is what he required to hit.  The Daemonblades don't wake because his (modified) to-hit rolls were only 4 and not the required 6+.

Apologises for bringing up an old post

 

But a 6+ hit from a spirit host always causes mortal wounds as it's an unmodified hit. Even if it's got 2- to hit that 6 will cause mortal wounds only