If I apply a regeneration shield to a creature in response to lignify on the stack, does the affected creature retain that regeneration shield until EOT? Also, if a 3 toughness creature is marked for 1 damage and a spell gives it -2/-2, will regenerate prevent it from dying?
In regards to your first question: Yes; the regeneration shield is not an ability.
In regards to your second question: Yes; the lethal damage would destroy it as a 1-toughness creature, so it is regenerated.
Lignify
In regards to your first question: Yes; the regeneration shield is not an ability.
In regards to your second question: Yes; the lethal damage would destroy it as a 1-toughness creature, so it is regenerated.