Anybody else notice that the Mana reduction cards actually increase the mana use instead of decreasing the consumption - as if the math multiplier was the opposite. Was playing a single lane game and before drawing the reduction card I had no issues with mana consumption and afterwards the consumption almost double on the very next turn. Pretty sure the developer does not understand working with fractions

second this, can't support level 2 obelisk with mana 15/s and 3 efficiancy upgrads... didn't notice this in my first runs, but now i got "lucky and got the upgrades early and it ended my run...

Works for me but generally the efficiency upgrades come after the health bonuses so its usually later on.
Obelisk just take an obscene amount of mana...
Each upgrade is just 20%