Afterthought

While Afterthought is equipped to a creature not
named Vecna, equipped creature gets +2/+0.

While Afterthought is equipped to a creature named Vecna, equipped creature has vigilance and wither,
and "Whenever a creature blocking or being blocked
by equipped creature has its toughness reduced
below 1, its controller rolls a d6 and takes damage
equal to the result, then you gain 1 life and surveil 1."

Equip {2}