"Any enemy model that is in base contact with a Tyranid with one or more lash whips counts their initiative value as 1 until the end of the assault phase, regardless of their actual initiative value."
Lash Whips are addressed in their FAQ (Tyranid FAQ pg 5):
"Q: If a model with Lash Whips is attacking a model with an Initiative-boosting rule/piece of wargear (e.g. Furious Charge, and Eldar Banshee Mastk, etc), which order are the Initiatives modified? (pg83)
A: As a 'set value modifier' the lash whip effect is applied after all other modifiers. If the model is effected by another set value modifier, roll off to see which is applied first at the start of each Fight sub-phase."
The 6th Ed Rulebook on the fight sub-phase:
"At the start of each Initiative step, any model who's initiative is equal to the value of the current initiative step, that isn't already in base contact with an enemy model must make a Pile In move. A Pile In move is a 3" move that is performed..."
"Models make their attacks when their initiative step is reached, assuming they haven't already been killed by a model with a higher Initiative! If both sides have models with the same Initiative, their attacks are made simultaneously. Note that certain situations, abilities, and weapons can modify a model's initiative".
So let me set up a theoretical scenario:
Say you have a Marine A, B, C... all I4 in one unit.
Tyranid Warrior unit with lash whips charges them through cover, the Warriors will strike at I1.
One Tyranid Warrior make it so Marine A is contacted. Marine B and C are not. Marine A now 'counts' his initiative step value as 1. Pretty straight forward.
Initiative 4 rolls around. Marine B and C pile in as they are not in base contact.
Marine B makes base contact with one of the lash whip models. Marine C does not. Marine C is still I4. Does Marine B now 'count' their initiative step value as 1? Does this mean they do not strike right now even though their initiative step had started at I4 and piled in at I4?
Marine C still strikes at I4 if engaged, this is pretty clear.
Marine A definitely strikes at I1 simultaneously with the Tyranid Warriors.
If Marine B 'counts' their Initiative as I1 after making base contact with the lash whip model during pile in, what to do with Marine B at I1 if Marine C kills the Tyranid he was in base contact with (assuming the Tyranid pile in move did not bring him into base contact again).
So does Marine B pile in a 2nd time? Or no?
I know how I think this should resolve according to RAW, just looking for opinions on what others think, and especially to make sure I'm not missing something else somewhere.