{Liliana, heretical healer}
If she's at loyalty 1 can I use her minus to get whatever Cmc creature like {reality smasher} I want because she's going to die anyway
No you cannot. It's similar to the life principle where you can't pay more life than what you actually have. In this case, you can't remove more loyalty counter than what are actually on the planeswalker
In this instance, you decide the value of X when you pay the cost. As stated by Indianslayer, you cannot pay a cost if the counters aren't there. As such, the only legal choice for X is 1.
Quote from: GlowackAttack on February 27, 2016, 08:42:48 AM
or 0 if they have {ornithopter} or {memnite} or {shield wall} or {dryad arbor} hahaha
Yeah, true. 0 or 1 indeed.