You cant respond to the act of ending a turn, but you can respond to the spell or ability on the stack that has that effect
Black removal spells pave the way for creatures like Gix, Yawgmoth Praetor, Phyrexian Fleshgorger, or Nethergoyf to get in
Since it targets a player and not a permanent itself, you don't have complete control over which enchantment gets sacrificed, though you're obviously aiming for someone who only controls one enchantment anyway
Since necroskitter says "when a creature with a -1/-1 goes to the graveyard, put it back in play under your control", the land is a creature that went to the graveyard
However, gaining access to the Monarch mechanic and both Black and Red cards positions her as a force to be reckoned with
As far as flavor goes, I think the card does a good job of showing that Leia is a great leader of the Rebellions since she makes them stronger, and she herself gets stronger the more backup she has