They main problem is we are not talking about just one RNG roll.
You have like 4 of them.

RNG roll = what cards you'll get with random on.
RNG roll = what rule will be on the match with roulette.

And if you win....

RNG roll = will a card drop or not
RNG roll = Lightning

Some RNG is fine, but RNG over RNG over RNG is plain stupid.