Real talk, having a 6 pack and not being able to deadlift at least 315, bench your own bodyweight or squat at least 365 is weak in my opinion. Getting a six pack involves a lot more than ab exercises, you have to lower your bodyweight enough to show your abs.
6 packs aren't hard to get or keep, and you shouldn't tailor your workout around attaining that goal.
1 other thing, the best exercise I've found to strengthen (notice how I didn't say to get a 6 pack) is hanging leg raises using a pull up bar. Most people refuse to do them because they find them too hard, my answer sack the fuck up and do them.