You do realize hes actually called M-A-O-K-A-I not maokia

I go with death fire because it ends up being cheaper to buy with Kages pick in inventory. I find it difficult to get to full build and its the last item in there. Otherwise i would go for a more optimal item, the logic behind it is simply the gold per 5.

not bad support build.
I would just change death fire to lichbane or tri-force, b/c u auto-atk in team fight to use his passive and they both have a 2 sec CD, better then the 1 min Cd on deathfire.
And with the CDR from the other 2 active items the proc timing is very short.
over all the damage output would be more constant and you would have more tanking stats (LB -> MR, tri-force -> HP).