
There spawn point is entirely random - I've had him right on the waypoint, at both the entrance and the exit to the zone and a bunch of other places. Odeg the Keywarden can be found in the Fields of Misery. I realize that it might not be feasible for everyone to farm these at MP9 but regardless, I found that on this difficulty combined with Nephalem Valor you could get guaranteed drops. Without 5NV I was not seeing a guaranteed drop on this difficulty either but when I got 5NV on MP9 I got a key every time. I then tried at MP7/NV5 and found that the droprate still wasn't 100%. I tried at MP7 without 5NV and found that at least on the first kills I was not getting the Keys off the wardens. I ran a few test runs to see about the droprates of the keys and noticed a pattern. Additionally, in order to be able to combine the machines, you will need a level 10 Artisan (Blacksmith).

There are 4 keywardens you need to defeat in order to be able to assemble Infernal Machines although the one in Act 4 is someone you won't need to revisit for each machine as he's the one that drops the plan for it. I ran a few tests on the droprates and hopefully my input here can be of some help.

I do realize that there already are several guides (and videos) going around with info on how to combine the Infernal Machine. Last updated at 14:00:17 UTC Weekly Help Desk RAGE Loot Thread Trade Thread
