The big gacha rolls that give 10 characters at once cost 300 "Tank Souls" (premium currency, basically), so I wouldn't spend all of them immediately. I save up a pile of them for the event gachas.
You can buy Tank Souls with real money, but I prefer not to put my credit card info into something where I can't read the fine print (or most of the regular print for that matter). I wish they had a global version that took PayPal or something that US people could access more readily.
Tank soul!!
The soul of a tank!!Sorry!! There's just no way I can sell my soul!!Never mind, just roll your gacha.It's Effective Use of Tank Soul!!Whatever are you talking about?What a wonderful name huh!!
I'm looking forward to increasing this!!It's for spinning gachas and expanding your tank warehouse, so use it fully when you collect it.
Tank Soul
Use up my soul!?
What a funny thing to-.....If you allow me the use of your unused possession, I'll be sure to make it bloom brilliantly.WHOA~~
The words of temptation!!It's Super Rare!