Japanese Box
Overlord is one of the most famous of Japanese exclusive releases and is one of the most gimmick laden Transformers ever released in that he is a double Powermaster as well as being a Duocon (of sorts) and a Triplechanger. There was also a European release of Overlord (an English version box in the UK which was a Woolworths exclusive) and a multi-lingual box which was available in mainland Europe.
European Box
The interesting thing here is that the box art on the European release was changed from the Japanese version.
Box insert
Overlord came with a lot of detachable parts which is why loose complete examples are pretty hard to find.
Robot mode
An interesting thing to note is that Overlord was designed as being an Autobot which explains his not-so-evil appearance. The face looks kinda friendly... Overlord is a huge robot, but we'll come back to that...
Close up of robot
The double Powermaster feature is used a lot in this toy as the Powermasters are needed to transform it from one mode to another, but when the engines are inserted into the robot's chest, the spring loaded guns in his abdomen pop out.
Base  mode
The base mode is a 2 foot wide sprawling playset that can be used with Micromasters.
Tank half of vehicle mode
Overlord splits into 2 vehicles: a tank (above) and a Lockheed SR-80 Blackbird (below).
Jet half of vehicle mode
Just to give you an idea of scale, below is a picture of Overlord next to a Soundwave.