Every card has three parts to its cost
Cost to draw [CoD]
Cost to play [CoP]
Cost to keep [CoK]
If an ability is only present while the card is around (Flooding) then it should be balanced against CoD+CoP+CoK
If an ability is present only after the card is played (Spark) then it should be balance against CoD+CoP
If an ability is present without having to play the card (Minotaur's discarded ability) then it should be balanced against CoD
Minotaur
Costs
CoD = 1 card slot in the deck + drawing that 1 card (+ 1500e when upgraded)
CoP = 4
CoK = the opponent not caring enough/unable to destroy it
Abilities
Discarded damage (CoD only) = 12|15 damage
Stats (CoD + CoP) = 4|4 (5|5 upgraded)
since these are mutually exclusive abilities the two calculations are independant of eachother
The stats are on par with the norms for the costs incurred.
The discarded damage needs to be adjusted to be balanced with only the CoD (or find some way to increase CoD)