You are on the offensive when you hit someone with a DP; you just usually don't have a followup because it defeats the purpose of a DP if you can follow it up. Mitsuru has a followup, so it might as well be a strange blockstring.
okay, i think we're getting terminology confused, or you think i mean something when i really don't. what i meant by offensive, is you're on the attack, you're going to pressure them, you have the right of way to do what you want to them. when you hit someone with a dp, you are interrupting someone's pressure. however, you don't get great oki after a DP, you don't get good mix up, you don't even get great damage. the only people who get more after their r action are yosuke, teddie, and kanji. everyone else, to the best of my knowledge, returns the game to neutral. yes it's a blockstring, by the technical sense, but ending your blockstring with a dp or a super is awful.
What puts the blockstring in Mitsuru's favour is that it's relatively safe and it's off of a DP. That she has any ability at all to prevent an opponent from punishing their DP after it's been blocked is nothing short of remarkable; when most characters have their DPs blocked, they're getting CH'd with something slow. The meaty 2A option allows you to not get CH'd by the super but doesn't change the fact that you cannot punish after the super
again, it's not really a blockstring as far as the definition is used, and it's not safe by any means.
more than half the cast can prevent an opponent from punishing their DP by going double or nothing, however mitsuru is the only one who can guarantee that this gamble will be played because you can only punish her dp from the front. i haven't tested the meaty 2a option, and i can't because i'm no where near a console, but i can believe that it works because it's also how you dealt with jin's c dp. but even beyond that, for the last time,
you can punish her in the air while she falls. if you have an 8 frame or faster move if you don't, then meaty 2a seems to work.
When you RC a DP in BB (acronyms everywhere) you can't just start pressuring again because if your opponent reads it correctly (which isn't hard, considering they have no other option other than get CH'd) they can DP you for free if you try, unless it's Ragna's DP and you RC'd it on like the first possible frame.
i feel like you don't read my full posts, which kind of makes this irritating to keep repeating myself. also this paragraph is hard to understand, and it's not because of the acronyms. i think what you're saying is "when you rapid cancel a dp in bb, you can't start pressuring because if the opponent knew you were gonna dp, they can then punish your dp with a dp?" please correct me if this isn't what you're getting at, because this sounds so wrong.
again, one more time, if you use your dp with the full knowledge that it's unsafe, then you're probably gonna rapid it the second it connects. that means that you get all the hit stun / guard stun without any of the recovery. this means you are at an advantage. using ragna as an example. if you do this correctly. ragna will dp and stay on the ground. he will be at an advantage. if you do this incorrectly, which i believe is the scenario you're thinking of is, he'll be in the air, which means that the guardstun is over and now you're at a disadvantage.
But isn't Bufudyne unsafe on block?
yes, which is another reason why this mitsuru dp shenanigan is a double or nothing gamble