I don't know if anyone is interested in giving me advise, or if I asked a hard question. I'll continue 'cause I feel like it.
I have done some more brainstorming and decided that the magic I want and the characters I want would work best with the folowing system:
The only magic is people who can bend metal. Metal does not have magical properties. People with the ability to bend metal study the physical properties of metals. So the magic people bend metal and stab people, then go home and invent AA Batteries and transistor radios. The only thing the bending does is change the shape of the metal. One detail that is missing is the hierarchy of which metals are hardest and easiest to bend with this power.
I don't think this information makes the question any easier, so I’ll ask a deferent one.
Which would work better in this Metal Magic World?
A) Giant golems made of copper, or tungsten etc.
B) Normal organic animals that grow metal plates or horns.
Metal animals would blend in easier, but the titans would go a long way to make the location more magical. OR!!! Mythical creatures with metal powers like dragons that breathe magnesium flames or gorgons that spit mercury from their eyes! This last one is kind one weird but it could pan out.