>>36672207There's nothing inherently wrong with those mechanics as long as they're balanced around them, either directly or indirectly.
Ultra Necrozma also makes you discard cards like many Fire Pokemon, but it's balanced by having reasonable damage output, a fair energy cost, and synergy with cards like Malamar and more.
Then look at something like pic related. It also has a discard cost, but it has abysmal energy costs and even makes you discard 2 for only 130 damage. Why couldn't this attack be [R][C][C] instead of needing two Fire energy? Why couldn't it only require one discard? Would it really be too strong if it did 150 damage instead so you could swing for 180 after Choice Band considering its current requirements?
Maybe I'm wrong and in a month some bizarre rogue deck will top with this Heatran, but pic related just feels like raw artificial design to me. I have no idea what justification the person balancing this card could have had.