Several other posters have discussed this: http://www.17thshard.com/forum/topic/53224-atium-alloy-powers/?hl=%2Batium+%2Balloys http://www.17thshard.com/forum/topic/53832-there-are-2324-main-metals-pre-harmonium/?hl=%2Batium+%2Balloys
The ideas and thoughts of the others are excellent and I wish to give them credit for their theories. If I have missed a theory that touches on a few things in here without citation, my apologies. With that said, I would like to present my opinion based on my understanding of the current known magic system.
Before we begin I would like to paint a major and well known difference between preservation and ruin. Preservation can listen, see, and understand the thoughts of man (internal cognitive sharing via pulling). While Ruin can speak and enter the thoughts of man (external cognitive force via pushing). The internal vs external balance may be a key to how the alloys of the god metals work. In one of the above posts, the OP discusses their theory of larasium alloys as gifting the burner the ability to become a misting. I 100% believe this theory as well. It is very much like preservation to preserve the essence of the metallic ability. Diluted forms of the pure metal that invested a human with that essence would indeed coincide with the preservation-like ideals. This is a very internal effect caused by the burning of the metal. Metal burning away is in way an act of ruin. The user consumes metal and burns away the metal until there is nothing left. However, larasium metal burning is not something that just goes away. The essence of the metal is stored within the user, preserving the essence and giving the user something more. I agree with another OP from a post above, that atium alloys change the way that the metal burns. However, I disagree in the effect upon burning. I believe that atium alloys are all external in a sense. Many of the replies in that post point at this. I also believe that atium alloys are in some way diluted forms of pure atium just like larasium alloys. How could one dilute atium (the ability to see all of the immediate futures of nearby people)? I think that the information gained from burning atium is too vast for a person to really understand what they are capable of (just like a new mistborn unaware of their powers). It is possible that someone used atium and their first use of it relied heavily on one effect. You can only burn it for a very short period of time so testing theories is not something a typical misting/mistborn would spend their time on pre-harmony era--especially as it was so expensive. I think that seeing the immediate future of everyone around is very valuable in a fight especially in an era of swords and H-to-H combat. It is possible that atium can be channeled or used in other ways than seeing into immediate futures. So the use of atium channeled into the reverse of electrum (seeing into others futures) may be the most valuable form of atium-alloy in that era. Reverse electrum may have been the only form of pure atium ever explored. This could explain the name malatium. So I will cast away this name for now as it may just be the name that was used to describe the 11th metal as it produced the reverse complement of what atium was known to do. Instead I will use the prefix 'ati-' to describe these god metal alloys. There for the atium use we know of will be ati-electrum and malatium will be ati-gold. I believe that all of the 16 original metals are forms of the 'self' power, while ati-metals are 'non-self'. Some of these will be obvious while others may be less so. But I would appreciate feedback and thoughts on the theory written below. Here is a list of the original 16 metals and their abilities (thanks to one of the OP above for list):
Steel ( self Physical External Pushing) - Push on nearby sources of metal
Iron ( self Physical External Pulling) - Pull on nearby sources of metal
Pewter ( self Physical Internal Pushing) - Increases physical strength
Tin ( self Physical Internal Pulling) - Increase senses
Brass ( self Mental External Pushing) - Soothes (dampens) emotion (of others)
Zinc ( self Mental External Pulling) - Riots (enflames) emotion (of others)
Bronze ( self Mental Internal Pushing) - Allows one to hear allomantic pulses
Copper ( self Mental Internal Pulling) - Hides own allomantic pulses in cloud
Nicrosil ( self Enhancement External Pushing) - [Enhances] allomantic burn of target
Chromium ( self Enhancement External Pulling) - [Wipes] allomantic burn of target
Duralumin ( self Enhancement Internal Pushing) - [Enhances] the next metal burned by user
Aluminium ( self Enhancement Internal Pulling) - [Wipes] Internal allomantic reserves of user
Bendalloy ( self Temporal External Pushing) - Speeds up time for those in bubble
Cadmium ( self Temporal External Pulling) - Slows down time for those in bubble
Electrum ( self Temporal Internal Pushing) - Reveals your own future
Gold ( self Temporal Internal Pulling) - Reveals your past self
Possible atium-alloy abilities:
ati-Steel ( non-self Physical External Pushing) - Forces another to push (or repel) all nearby sources of metal
ati-Iron ( non-self Physical External Pulling) - Forces another to pull (or attract) all nearby sources of metal
ati-Pewter ( non-self Physical Internal Pushing) - Increases physical strength of another
ati-Tin ( non-self Physical Internal Pulling) - Increases senses of another
(This block and the next block were very hard as self and non-self are sort of part of two of these metals already. I would like you to think of brass and zinc as target mental changes of the USERS desire. Non-self could be the desire of another person to change surrounding emotions. Though this may be a stretch, but hiding ones pulses in a way is keeping to oneself. However if you projected those pulses in the cloud instead you are sharing your pulse with others.)
ati-Brass ( non-self Mental External Pushing) - Allows another to soothe (dampens) emotion (of self)
ati-Zinc ( non-self Mental External Pulling) - Allows another to riots (enflame) emotion (of self)
ati-Bronze ( non-self Mental Internal Pushing) - Force others to hear your allomantic pulse
ati-Copper ( non-self Mental Internal Pulling) - Amplifies (intensifies) the pulses of user and those in cloud
(As mentioned in previous block self and non-self are sort of part of this regime. I would like you to think of each metal in this regime as a user benefit or a target benefit not self and non-self already. It is possible to be both non-self and user, self and user, non-self and target, and lastly self and target. Here we describe the non-self user and non-self target. We will also replace the previous [enhance] with [surrender] and the previous [wipe] with [provide]. The below works as the abilities used and metals burned are not of self but of non-self).
ati-Nicrosil (non-self Enhancement External Pulling) - [surrender] user metals for benefit of target. (This would
enable someone you touch to access your metal reserves). ati-Chromium (non-self Enhancement External Pulling) - [Provides] wild card burning of next metal by target.
(This allows target to burn next metal for an ability
they already posses)
ati-Duralumin (non-self Enhancement Internal Pulling) - [surrender] others metals for benefit of user. (This
would allow user to access the metals of others nearby
as your own reserves).
ati-Aluminium (non-self Enhancement Internal Pulling) - [Provides] wild card burning of next metal by user.
(This allows user to burn next metal as a wild-card for
an ability they already posses).
ati-Bendalloy ( non-self Temporal External Pushing) - Speeds up time for others nearby (tire-shape) not
the user and not people outside that ring. ati-Cadmium ( non-self Temporal External Pulling) - Slows down time for others nearby (tire-shape) not the
user and not the people outside that ring.
ati-Electrum [atium] ( non-self Temporal Internal Pushing) - Reveals the futures of people nearby
ati-Gold [malatium] ( non-self Temporal Internal Pulling) - Reveals the pasts of others nearby
Thanks for reading. I hope that if anything this was thought provoking. As one of two asides, I believe that the main purpose of atium (ruin essence) is to 'use up' scaradel metals (depleting them forever). As I mentioned earlier preservation alloys would preserve the essence but it is my thought that atium alloys are a tool of ruin to catalyze the ruination of metals on scaradel. Below is a link to another post on this matter. The second aside is the use of atium for metalminds. I believe that any metalmind atium alloy will be able to store non-self attributes. Storing another persons weight, strength, health in place of your own. Any thoughts? I will attach a link to a simultaneous post about a theory of the fate of all metals once I post it in a few minutes.