Magic crystal question

[QueenGhidorah]

I don´t know if they are called that in English. I mean the ones that reduce mana cost for spells that are further away.
I wonder if the effect stacks if I have more than one. I am in the second campaign level and don´t want to waste my precious coins to try it out. Anyone here who knows?

[QueenGhidorah]

Okay, I got myself another one and tried it. First I thought it wouldn´t stack because when I put another crystal in my base it the amount of mana needed didn´t change. Then I tried putting the crystals further away outside my base. That did the trick. Near where I put them down the amount of mana for the portal is 2 now. So they work more like a beacon, I put them down in the area where I dig and save lots of mana. I just got wrong how they work in the beginning :)

[Ainz Ooal Gown]

They reduce mana use the further you get from the main portal.
It is the most useful on the cave map, because that is the biggest map in the game.
Imagine circles around the main portal that is where the mana cost increases. When you place the crystal the most inner circle disappears and the second nearest one to the portal will now make the portal spell cost 3 no longer 4

[Diego Pesente]

THe crystal works as a relay, the mana cost gonna be from the closest crystal or main stockpile, so if u wanna shoot on the lava level or near the map edges whitout a huge mana cost, bring some and place they there