Since all the magics have something to do with metal it seems like "they" might not have bothered to reference metal in the name. "Allo" implies the alloys that allomancers use in addition to the pure metals. "Hema" would nicely imply the blood involved in the creation of a steel priest, while "Exo" implies the unique trait that Sazed's magic has of being able to use metal on the outside of the body.
Excellent point.
I like the -chemy, and do not htink you should use -mancy or -lurgy again. Other latin roots that could describe what Terrismens' power does:
resto- (to await, be in store for the future)
restochemy recondo- (to put away , put back, store, hide)
recondochemy condo- (to put up, put away safely, store, to hide, withdraw)
condochemy cella- (a storeroom , or a garret, mean apartment)
cellachemy abdo- (to secrete, hide, to put away , withdraw, remove)
abdochemy amolior- (to remove by an effort , set aside, get rid of)
amolchemy repono- (to lay back; to put aside, lay up, deposit, store)
reponchemy sevoco- (to call aside, withdraw, separate)
sevochemy avoco- (to call away , or off, to withdraw, remove, divert)
avochemy detractio- (drawing off , withdrawal, taking away)
detrachemy mando- (to commit , entrust)
mandochemy aspiro- (figurative: to infuse spirit, etc)
aspichemy compleo- (to fill up)
complechemy cumulo- (to heap up , pile up, increase, heighten; to fill up, overload)
cumuchemy gravidus (heavy; laden , filled, full; pregnant)
gravichemy perfundo- (to steep in, fill with)
perfuchemy attineo- (to hold, keep, detain)
attinechemy capio- (to take in, hold, contain, keep in)
capiochemy distineo- (to hold asunder , keep apart, separate)
distichemy sospito- (to keep safe , preserve)
sospichemy My favorites: cellachemy, abdochemy, amolchemy