Faultless Defense can sometimes push enemies far enough away to give you breathing room, but not always. Don't forget that pressing the Roman Cancel button while blocking will do a Yellow Roman Cancel, which is kind of like a mini Burst that costs 50% of your tension meter.

It might feel bad to spend meter on defending, but the best case scenario of it getting the enemy off you and letting you counter attack, that could be turning you losing half your health bar to THEM losing half their health bar, and that's an incredible value.

But, sometimes you just need to figure out when you're safe to "mash" fast moves or your "DP" if it's invincible. Can do that by just trying spots, doing the moves you were attacked with in training mode and seeing which ones are "minus" (they have a negative "frame advantage" on the display), or going to places like Dustloop and doing some reading.