The Energy Manipulator is an NPC that can be found in any of the major cities. This merchant will let you exchange your energy for powerful mounts, and also offers the option to transmute your energy into runes, souls and relics.
The Energy Manipulator offers four rare mounts in exchange for energy, as well as a fixed amount of materials and a base mount. At the time of writing, this list includes:
<aoitem size="75">Siege Ballista</aoitem> Siege Ballista
<aoitem size="75">Flame Basilisk</aoitem> Flame Basilisk
<aoitem size="75">Venom Basilisk</aoitem> Venom Basilisk
<aoitem size="75">Elder's Command Mammoth</aoitem> Elder's Command Mammoth