Last power gem [spoilers]

[Exila]

cant find last gem for balance essence for the hub boss, got 1 from fire golem in desert, 1 from boss in castle, 1 cant remember where ), where can be last one ?

[itsmemario]

It can be everywhere! Go in all dungeons again and look for it. Normally you can hear it even if you are far away from. There is no other way as to search for it.

[Jirodyne]

Indeed, it can be anywhere, because you can get every power gem, except the first 1-4, in any order you want in any way to want. Because of this the 'last' one is always different for every, EXCEPT in they have them all and did everything in the game before going to the Castle, which a lot of people probably end up doing to do all optional things before the end, at which case the boss on the Castle Roof will have the Last Power Gem for most people.

My best guess is opening the map, and making sure you have explored EVERYwhere, and have done EVERYpuzzle. Also that you have visited every place.