Aside from that, the "super-quick-swipe attack" always comes after a backstep, so as long as you don't actively pursue her you should have enough horizontal distance to escape its range. It also has a somewhat low-ish hitbox and fairly lacking vertical range, so if you're high up (e.g. your neutral 3rd attack or during a jump) it will likely miss you.
Slide kick is still probably the most useful attack in the fight, because it gives you a fair amount of horizontal distance as well as allowing you to dodge under the teleport-grab and thunderball moves.
The "too fast to be undodgeable attacks" in this boss fight is probably closer to the spinjump she tends to spam after reaching 20%ish HP anyway. That thing has even shorter startup than the swipe and takes some precise timing to slide under.
Fighting the succubus in Hell difficulty took me a lot of save-scumming. Though that might also be how I'm not very good at action games.
Slide kick is still probably the most useful attack in the fight, because it gives you a fair amount of horizontal distance as well as allowing you to dodge under the teleport-grab and thunderball moves.
The "too fast to be undodgeable attacks" in this boss fight is probably closer to the spinjump she tends to spam after reaching 20%ish HP anyway. That thing has even shorter startup than the swipe and takes some precise timing to slide under.
Fighting the succubus in Hell difficulty took me a lot of save-scumming. Though that might also be how I'm not very good at action games.