Engineers didnt want to kill the Humans on Earth.

Well, couldn't there be different castes instead of races? The engineers and humans seem to be different races since their DNA match? The cloaked ones could be the rulers or a religious sect? We then have technicians, ordinary workers etc, and perhaps women somewhere?

The awoken engineer was very hostile towards humans from the beginning and killed all of them (except Shaw) which could suggest that they are disappointed (or perhaps threatened) by humans and want to wipe them out and start all over again?

I'm thinking the LV-223 Engineers HATE Xenos, and they just see us as incubators.  The thinking behind this is TL;DR so I'll leave it out.

Remember, they turned a site that appeared to have religious significance into a weapons cache/factory.

Or weapons are their religion.

And it wasn't Shaw's assumption they were going to destroy us; it was David's.

@S.M the cargo hold full of black goo canisters headed for earth didn't require a huge intuitive leap given its obvious effect

The LV-223 engineers may have been worshipping weapons, but the other set seemed to place great significance on seeding life and the Xenos. They clearly have different values.

Or they simply changed over the course of hundreds of thousands of years.

Shaw could've worked things out but when she saw the canisters on the ship, she didn't know where it was going.  David had to tell her it was going to Earth and 'in order to create you must first destroy'.

S.M. you're observations in the other thread about the star chart tablets prove that the LV-223 Engineers have a different agenda than the ones visiting earth because after the LV-223 Engineers are all but wiped out, the others kept doing the same thing they'd always done on Earth.

The tablets prove they visited in the current era.  Beyond that everything is up in the air.

The catastrophe on LV-223 happened about 2000years ago +/- the youngest tablets were dated 13-1400 years ago. Very likely after the incident.

Indeed.  But that doesn't tell us anything beyond the fact we had recorded visitations in the 7th century.  Everything else is speculation.  Perhaps Covenant will shed more light on things.

Its pretty much very open..... its one of the beauties about it all.. its so open to which way they could go...

I think again maybe David was not telling the truth at all or using miss-direction... but i like to think that actually he is spot on with what he had found out.

*The Urns are re-weaponized they are used like a Weapon.

*The effects will as far as movie showed, Mutate/Evolve Life that would have Xeno related DNA added to its Gene-Pool, everything infected would be evolved into something new.. destroyed in the process as far as having any conscious really of its old self... perhaps.. it retains something but not much.

*The ship was heading to Earth and so if it used the Urns, Life on Earth would in one sense die... but from it would evolve something new.

so the big question is when was the Urns made,  did Mankind upset the Engineers at a certain point and they then created this Weapon purely to destroy us.  So it was purposely created for the purpose of our destruction after we had finally done too much that they deemed we needed the Plug Pulling.

Or had a faction had created either on purpose or accident something related to the Xeno, that they worshiped for some reason and felt its DNA was more superior than their own DNA which is used to seed life?

Maybe this was going to be used on other worlds as a experiment or against their creators or other faction.

But then after they had came across what ever leads to the Mural.... Mankind had then upset these guys and then they thought.....  "you know what, we tried but you guys just ant worked out the way we wanted"  Maybe its time to test this new strand of DNA on a World and upgrade Life with its DNA...

Than our own Engineer DNA

"The catastrophe on LV-223 happened about 2000years ago +/- the youngest tablets were dated 13-1400 years ago. Very likely after the incident."

Indeed and i tried to cover some reasons for this in a other thread the other day....

Re-post it here....

================================

As for the other Star Maps after 2000 years ago...

Well this is the grey area... its another area we cant get to  ONE working explanation..

*Did Engineers forsake the Cradle of Creation area, and after the failed attempt to destroy us...  they decided to forsake us... but they came back to still deal with other areas on Earth where there rituals and worship to the Gods had not offended them.

This leaves a Plot Hole to where have these Engineers gone?

*Did some faction who prevented the Mission, and maybe caused the Outbreak.. come down to Warn us... but these warnings why only in those other cultures far away from Europe, Africa and Middle East.  Then again we ask where did they go.

*Was as i mentioned prior there other Emissaries sent to other places, who after the abandonment of Mankind after the failed destruction of us... and fall of LV-223.... did these Emissaries remain in other areas and continued to interact with Mayan's and Polynesians . What happened to them?

*Or was the interactions from way before those later Star Maps but the tales of these Gods kept being passed down generation by generation in these Less Corrupt areas/cultures and so its a passing down of the tales, and then a re-creating of the Maps shown to ancient ancestors rather than any actual Engineers interacting after the Outbreak?

All a lot of ideas thats hard to say which would fit...  I would say the last TWO make more logical sense and less Plot Hole.

@S.M. speculation is pretty much all we do on this site.  Kinda the whole point.

Absolutely. Not disputing that.

There is, of course, a difference between speculation and 'proof'.

You may be quite correct that there's another faction of Engineers with a different agenda - but it's not proven.

Another faction of engineers with different agendas its not proven but one faction of same angineers with same agenda is not proven either.

So speculation is healthy, fact or proof is claiming engineers made us.

Fact or proof is claiming xenos are deadly.

The fact they visited us after the incident doesnt mean they did it with good intentions as pior the incident.

They were still pointing to the same star pattern so who knows.

Edit - double post

Ye true. Hopefully ac will be more revealing indeed cuz atm im confused,i would like tho there was no factions.

The Engineers didn't want to destroy us, they simply created us into.... something. Since it doesn't really kill, it actually does the complete opposite. It mutated Fifield into something but didn't kill him, and also made Shaw give birth to a trilobite which is argumentatively a queen (bred through engineer). So, the black goo is not meant to destroy us.

It's not meant to do us any good though.

From memory, Ridley says that what happened to the decapitated Engineer, would ultimately be the fate of Fifield and Charlie. ie. their bonces would explode.

Plus anyone infected like Fifield would kill a bunch of people in the process.

OP: your point is spot on. There are a lot more efficient ways to wipe out the life forms on any given planet. But in this story, Ridley posits that life is the result of a bioform experiment that has this black goo as a catalyst. I truly believe they wrote themselves in a corner with some of this stuff. Then made it worse with the final edit. We can thank lindeloff as he was the one who sold Ridley on using hints to concepts then moving on to the next concept to keep everyone intrigued expecting an answer, and never getting one.

Just a quick thought about why 2 more engineer visits after the botched goo bombing 2000 years ago on the Romans; is there a consensus on what the pictograms actually were? An invitation or a warning? 

If invitations, that means their homeworld is in that system of stars. And so they found the most amenable culture of that time to relay the invitation to. But the Mayans were wiped out, and the Polynesian became war-like and chose terrestrial Gods. This was probably the proverbial "last straw" and they just gave up on us. Or something in the Engineer culture had changed and/or they no longer travelled through interstellar space. We just can't know for sure until we are given an exposition scene with David. He is the only one who can read and speak "engineer". 

If the pictograms were warnings, I'm baffled.