also how the key is used??? will you get a random unit that you dont owned??? because i probably use 10 of them and didnt get a duplicate unit.
also how upkeep works? does unit on the squad counts taXes or all unit you own counts?do you need to fire units to save upkeep cost?
The key is used by pressing the 'use' button. You use 1, 4 or 10, by setting the appropriate button to that (next to the buy key).
And yes, you get a random characters. All characters seem to be unique though. So you can't get duplicates. 10 keys guarantee a rare unit(like the ceo characters, mascots, or actually good rare units -- because the ceo and mascots are pretty shitty)).
As for the 'upkeep': you only pay when you use units.
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For everyone:
the resources I used -- because the interface and information you get from the game are pretty shit-tier:
skill manual(English) --
You must be registered to see the links
the complete Japanse wiki (use google translate plugin -- it works pretty well) --
You must be registered to see the links
Ps.
In the main menu, there is a tutorial that you'll never get to see if you just start a new game.