Can this anime be identified by a small number of disconnected scenes?

Question

Please forgive me my somewhat lengthy preface here.

At best I have to estimate that this anime was aired at least 14 years ago. I don't recall it being part of a series, so I'm fairly certain it was a one shot movie. Never can be sure though.

All I can really provide for identification purposes is a small handful of scenes. I am unsure if these are all even from a single anime. It may well be 2 different ones that my memories have somehow merged to form a full concept. Hopefully someone will recognize at least one of these scenes, otherwise, I'll need to find some way to wipe these things from my memory and forget they ever existed:

Scene 1

Takes place on a star ship A tall alien with a disc like head. At some point the monsters head detaches from its body and begins to fly around independently. That is all I can recall from it.

Scene 2

Takes place on a planet near some teleporters?

A woman is fighting the alien, hears a voice (her brothers?) telling her to use or run to the teleporter. It later turns out to be a recording. There was some emotional connection between the woman and whoever's voice it was.

During the fight the monster gets caught in an explosion and blown into a building, one of the teleporters I think. It walks out of rubble with something impaling its head. It doesn't appear particularly phased, but woman seems to make special note of the injury, as though it was somehow unexpected.

Scene 3

The woman, older male and youger male (possibly a child) are driving, in a tunnel or under a bridge, or just some dense cityscape. I just recall the environment being very crowded.

At some point they run into quadripedal monsters of some sort and wind up running a test one one, determining that it is somehow related to the main antagonist.

Scene 4

The main antagonist alien/monster appears to have placed a beacon (for some reason it strikes me that the beacon was organic in nature) on the roof of a building to start calling in more of its kind from off world.

Scene 5

Takes place in a desert setting. The woman confronts the monster. The woman has a staff of some sort, it was shown earlier in the movie, I believe by the younger boy. When the tip of the staff is pressed into the ground it generates a forcefield that surrounds the staff and its user. the tip is pressed into the monster, causing the force field to cut the creature in half horizontally.

The top half falls towards the woman and the "face" of the monster extends from the head to attack her. It turns out the things neck was its only weakness. As it is falling, someone, I believe at this point backup had arrived, takes a blade and cuts into the things neck, and then slices it down length wise, cutting the face in half too.

If any part of these scenes can be used to identify an anime, I would be beyond greatful to know my mind wasn't playing tricks on me.

Answer 1

That sounds almost exactly like IRIA: Zeiram the Animation to me. (http://www.imdb.com/title/tt0107228)

I really loved Iria when it first came out, the action and character designs are excellent. Interestingly, this OVA is based on a live-action movie series called Zeiram (which I've never seen). I wish they had made sequels to this anime because I found Iria a pretty engaging character at the time (haven't seen it in forever). Her grappling hook thing was pretty slick and she kicked serious butt ;)

The alien (Zeiram) is pretty much unstoppable and has a creepy, extensible face (kind of like a Xenomorph). It can clone itself and absorb people. Here's the description of the monster (from http://myanimelist.net/character/21662/Zeiram#aJugBUYj0dqWceUH.99):

"Zeiram is the ultimate being and virtually indestructible. In addition to being extremely powerful, Zeiram can generate imperfect clones of itself to assist in battle. Zeiram also needs to assimilate other life forms in order to sustain itself, but in doing so it is thought that Zeiram can learn whatever is known by the organism being assimilated. Zeiram is not a unique creature and other versions of itself are known to exist throughout the universe. Later in the show Zeiram attempts to contact other Zeirams in order to bring them to Myce."

Hope that helps!