Minimally destroy CGCC in Game of Life
Score 1, 35 generations
Sorry, but I guess I wrecked the challenge. I brute-forced all meaningful one-dot additions by hand, and found no other answer that wins against this.
Raw ASCII format
 OOO  OOO  OOO  OOO
O    O    O    O
O    O    O    O
O    O OO O    O
O    O  O O    O
 OOO  OO   OOO  OOO

               X

Image of initial state

Copy.sh export
#C Generated by copy.sh/life
x = 19, y = 8, rule = B3/S23
b3o2b3o2b3o2b3o$o4bo4bo4bo$o4bo4bo4bo$o4bob2obo4bo$o4bo2bobo4bo$b3o2b
2o3b3o2b3o$$15bo!

Try this pattern on copy.sh!
Slow animated gif