Pitt

During which phase can I use the dread knight command ability with my vampire lord on zombie dragon ?

Lets say I have a hero like Arkhan and he attacks the unit closest to him and kills the unit with his first attack. Arkhan has 3 more attacks and another enemy unit is 2 inches away from Arkhan. Can I pile in with Arkhan and attack with my remaining 3 attacks ?

When an artifact weapon says "pick one of the bearers melee weapons to be...." do I have to pick only the weapons that my hero has or can I pick one of the heroes mounts attacks?

The GW store offers 5 different vampire lords for sale that all share the same warscroll, what are the stats for each one? I assume the one with the skeleton horse gets the "nightmare steed" ability. What about the other 4, which ones have "flying horror" and which ones have the "chalice of blood"?

Does arkhans staff modifier +2 to cast and +2 to unbind apply to endless spells. Also does his command ability "first of the mortarchs" also increase the range of the endless spells that I cast.

When determining if a unit or model is in line of sight for a wizard to cast a spell on. Do you measure from the highest point of the wizard model, for example the tip of Arkhans staff, or eye level of that wizard model?

The skeleton horde start collecting box comes with a warscroll battalion "arkhans skeleton guard". Arkhan, a unit of black knights and a unit of skeletons. Is this battalion legal in matched play and how many points does it cost?

I hate assembling them but looks like in order to get the most out of them I'll have assemble 10 more, thanks.

If I use a unit of 20 skeletons, that means that the attack characteristic for each model is 2. What if 1 of those skeletons dies and now im down to 19 skeletons, does their attack characteristic drop to 1 until I revive the 1 dead skeleton or will it stay at 2 because the unit started as a unit of 20 skeletons?