I have no idea y i have it but if any1 can tell me tht would b great

i found a single invoker jewel in kazes (i think thts his name) final battle arena in one of the fortreses

There is an area in the same fortress where you get the jewel. And there is actually few of them if I remember correctly.

Still looking; you get the Invoker Jewel after you beat Stone and it is located in a chest in the back middle up a slope after the fight. It says that it should be used on a Black Ring machine or something like that, but I can not find a machine to use it on.

Well I cant actually remember which fortress its from, but I am pretty sure that there is an area where you can get few more of these invoker jewels and you shouldnt miss the machine if you really been there. Beside follow on the boss route, which he teleport away 1st time if I not mistake, go search in other areas inside the fortress.

I only found 1 Invoker Jewel and I too don't understand "what" I can do with this item !!

I remember I find it by "Stone's" Fortress.

thts the same as me just 1 in stones but dnt noi the use of it lol

Search inside the flying fortress where you found it. Try to be more cautious on your surroundings. There are machines around in the fortress.

That last stone is confusing me as well. There was a machine you had to overload with invoker jewels to stop walking armors from spawning. All the stones needed to do it were readily available on the rods next to it though.

Not that I want to criticize or complain, but I notice majority just dont check up on the surroundings. I dont think the machines are really that hard to be spotted also

The location I was talking about was in Stone's headquarters. There's a room to the left that constantly spawns walking armors until you overload it with the jewels you find around it. This jewel was up in one of the arena shafts for some reason. I thought it could be one of the big metal doors in the arena but it's not. I also researched the Stone's Headquarters and none of those machines reacted to the item. I would search more, but empty fortress's are boring.

As previously mentioned, I dont actually remember which fortress its found. But there only 1 general which make you chase him into the arena in flying fortress, where 1 invoker jewels can be found after defeating him. After getting out from the arena, you will be back inside the flying fortress and I sure there are still unexplored area, if you just follow the general straight to the arena. The rest of the invoker jewels are in that unexplored part of the fortress, which I dont think its hard to be locate. You can actually forget bout it if lazy, as the reward is not something important also if I remember correctly.

That "arena" is for sure Stone's Flying Fortress!

and you, ACSS, found more than 1 Invoker Jewel?
Hmm, I think I'm missing something lol ...

Actually guys, with this post I hope to stop the discussion once and for all because those who don't know what to do are only being confused by posters who have done it but have no clear details on what to do with the Invoker Jewels.

In the final Interior Halls where you first meet and combat Stone (before he runs to the Arena) there is another hallway other than the short one to Arena teleporter. Down this other hallway is another small squad of Black Ring and also the re-spawning Summoned Armors. The trick of this location is that the machine on the other side of the room has to be overloaded. The problem is that it will require 5 gems to do it.

Now,notice the green gems on pedestals right nearby? There are 4 of them, so simply target them with your reticle (the "targeting circle" ) and take them as you would any other item. But the trick of it is that theres only 4.....you need 5 to overload the machine. Can you guess where the other Invoker Gem is? Indeed, it is the very one mentioned by several of you as being discovered after the Arena conflict with Stone.

Oh and btw, for those of you who may find Stone a challenge, use of Explosive Arrows skill makes him and most other bosses easy as pie, since at range they tend to favor lower damage/easily avoided attacks and the Explosive Arrows skill is quite effective at whittling them down.

Once you have all 5 of the Invoker Gems go to the control panel and it will ask if you want to use the 5 gems and simply affirm it and the machine will shutdown. As well, a small chest will fall at your feet with a mid-level magical item in it (I got some crappy necklace...didn't bother to reload to see if its a random-cycling item or static.)

And finally, as for the 4 massive steel doors at the end of the tunnels in the Arena, I believe them to be purely for show. Consider that you must eliminate the 4 Chief Minions and these would seem to be a theatrioal approach to appear as "holding cells" for them as any good arena has to have for its gladiators. Unfortunately no kewl CGI movie of seeing these creatures emerge, they simply pop into Arena in a flash of Teleportational Magick.....Weak! Anyhoo, i wasn't really concerned with seeing if I could get into Mumbo, Jumbo, Gumbo and Dumbo's little lairs since there doors are unpickable at 5th level and no keys drop from them or Stone.

*oh and also, for those of you who haven't actually fought Stone in the Arena yet those of course are not their real names, but since they weren't very impressive combatants I chose not to use their unduly impressive-ish names since all they are are a slightly overpowered Troll, Beholder, Demon and a new incarnation of a creature some sorta "hovering tentacle Cyclops" thing.

Thanks Jesterguy!!
Your explanation is clearly

I believe I found the other gems, but I didn't link these with the Invoker Gem I found in the Arena! Next time I do it better!

The four gems on the pedestals will shut down the spawning walking armors if you so desire but using all 5 will get the chest mentioned by Jesterguy.

I didnt get any Jewel from defeating Stone or his little minions. So where is the 5th one ?

In Stone's arena, the invoker jewel is in a chest near one of the cage doors (presumably where the summoned opponents came from); take the ramp up opposite the entrance ramp (the chest is by the centre cage door).

Great thanks, must've skipped that door somehow :p

In only takes 4 of the stones to stop the generator and they are all located right next to it. Then you cannot use the generator again and the 5th stone sits in your inventory forever far as I can tell

And so do the flower buds

It is better if you wait until you have all 5 of the stones, though, before using them (that will shut down the machine and spawn a chest). If not, at least the extra one doesn't count towards your inventory limit (same for the extra flower buds from Stone's fortress greenery), just a bit of clutter for the quest item section of your inventory.