Elven TK and Cubics !!!???

Hello...
OK I have a TK and just learned Cubic Mastery for 3 Cubics...
But since I just have 2 Cubics I wonder how this works... I try to summon a Cubic twice but dont think this works :p

Does anyone has some TK experiencse with Cubics???
Does my Chara summon them and i just cannot see them???
Those They cubics just last longer???
Cant be that i leran a skill who is USELESS...

So any help and info woudt be nice....
THx
Shadow

Cubic Mastery 2 is used to allow you one "spare" cubic from a summoner.

You can not get three cubics on your own, and actually, you can not receive two storm cubics by having a warlock summon a storm cubic for you either.

Hmmm sounds interesting...
but not sure i understand this spare thing... means some1 else can SPARE ME a cubic or I can SPARE a cubic???
Sounds pretty ood but my TK experience with cubics not so high ^^ I prefer my Gladi ;)
Thx for the info

A summoner gets a skill "Mass summon: [Storm/Aqua/Phantom] Cubic". It will call one cubic down for each party member. For a TK, without cubic mastery, one of his cubics gets replaced with the summoner's. If you have the mastery, you can keep the cubic anyway.

People without mastery can take only one mass cubic, of course.

ahhhh ok now i got it ;) sounds prety clear to me ...

THX THX