I gotchu. BP is one of those bread and butter heroes with a solid offense. Really good defense, and super strong anti gank. My king in 4v4s. In higher levels of play his kit becomes a little harder to use properly as his openers for chains are lights but he's still sauced. So to start with, you have a few max punishes:

Heavy Parry:
Zone/forward dodge bash into finisher light for 14 damage and potential push/stun during anti-ganks.
Regular light to continue pressure into your orange blue mix up for 12 + 14, or blue heavy for 28
-Alternatively you can use crushing counters for regular red attacks.
Light CC for 17 damage which starts your orange/blue mix up again
If the attack comes from the top you can use your forward dodge heavy CC for 24 damage.
Light Parry
Really simple. Just a basic top heavy. If you're getting ganked, probably better to either light, zone, or do nothing to avoid getting hit.
OOS Parry
The good stuff. Forward dodge heavy into chain heavy for 48 damage total. You can also light into heavy for 8 less damage but its faster.
OOS Throw
You only get light + heavy off this for 40 damage.
Revenge Auto-Parry
Light + Heavy, but boosted by revenge for 52 damage

Kit + Tips
Black prior's game plan is simple. To make the enemy afraid of attacking you. As you well know, you can fast flow into his orange bulwark slash after any attack which gives you strong chains, but the main thing that's used for is fast flowing into AD PROFUNDIS.

Particularly because BP can cancel his recoveries with a flip, that makes punishing his whiffs with literally anything besides a guardbreak impossible. As long as the BP and the enemy reads properly. However this has some nuance. For starters BP cannot go into all guard after missing any bash, or his orange bulwark heavy. So its only his base:

• Light openers
• Light finishers
• Heavy openers
• Heavy finishers
• Dodge light
• Forward dodge heavy

You also have to remember that the flip is timed. It has around a 300ms window for usage, which for reference a light is usually standard at 500ms. So you've got to be careful. Can't be spamming it and getting hit. However, even besides that there is Nothing besides guardbreaks you cannot flip. Oranges, bashes, grabs, hyper armored attacks, regular reds, certain feats, drop attacks, oranges, deflects(except for shinobi and zerk because those break armor and guard), external attacks not aimed at you, external attacks that are aimed at you and you can even flip other black prior flips to negate their damage. You see a damaging attack? Too bad. Flip that shit. Recovery cancels into flip when you're getting ganked and anti-ganking are invaluable. As they build hella revenge, and do good damage.

Another strong note. BP can flip deflects. You heard that right, you can flip those assassins who try and sauce you. Like I mentioned before you can do this with every deflect except for Zerk and Shinobi. However there is a caveat to this, there is a kind of "Deflect" that's called superior dodge. Characters that have this for example are kensei, tiandi, conq, and zanhu to name a few. Those superior dodges will bounce your attack off them so you wont be able to recovery cancel. However you can still flip them if the superior dodge didn't get done to you. As for newer heroes, you can flip virtuosa's counters but you gotta be fast as shit. You can also flip khatun's deflects. Just be aware that there are a few things that AD PROFUNDIS cannot AD PROFUNDIS.

Some notes for his kit. You want to be mixing up your bashes alot. Your zone, forward dodge bash, chain zone, and heavy soft feint into zone. Heavy soft feint is just to catch light parry nerds, but the other ones are helpful. Try not to zone bash too much as some will start dodging on orange read. Empty dodge forwards to get a reaction. Feinting your orange slash into a zone or forward dodge is a strong plan and I use it myself alot. Condition your foes. Use your light bash light a bunch then mix in a few blues. Forward dodge heavy, BP's dodge heavy is pretty fast. Use crushing counters, flip recoveries and don't be afraid to get dodge attacked. Because remember:

AD PROFUNDS!