"Sit down" Achievement and S Ranks in arcade

[WhoseWell]

How do i get "Sit down"? Just perfect guard him a bunch of times or something specific?

And how do you even get S Rank in the higher floors? Get hit twice and its A rank.
Even the hits on my barrier count for some reason???

Is the game just expecting me to no-hit all late game bosses or is there a trick i am not aware of?

[Faust]

When Marino catches you with his rapier - he performs a, uh, 4 or 5 strike combo, I believe. You have to perfect block every strike, which lands him squarely on his arse if successful.

And yes, indeed, you have to either no hit or get clipped like once for very minor damage if you're lucky, in order to S rank a floor (sometimes you can get A+ rank in damage if your damage received was considered by the game too minor, which together with a perfect S in speed will add up to an overall S rank on the floor. Get an A in any of the rooms and it'll be S-, which adds up to an A if you got an A+ in damage). The trick is to be very good at the game and, optionally, either have frosty to partially draw agro and suicide-charge particularly nasty enemies, or be a whole-ass ranged summoner mage, to be even safer.

Some perks and treats can help as well. No elites will aleviate a lot of headache. Time crystal will allow you to retry a floor, though that would add up to a -35% to your score so you'd have to even it out with a curse (one of the veterans recommends Big Brothers). Personally I didn't use time crystal in order to not have to bother with Big Brothers and be more consistent in the longterm.

Getting Lightning Potion can help a lot with free chip damage while you're dodging threats.

Keep in mind that bosses have different health scaling in the arcade. Sometimes with enough damage you can just skip 90% of the mechanics by bursting down multistage bosses like the Eye or the Mimic. Even someone obnoxious like the Priestess could have all of those nasty hoolahoop bits skipped if you happened across one of those worth-their-weight-in-gold bonus damage per gold / per battle room pins early on.

There is a thread somewhere in discussions made by one of the arcade veterans giving tips on S ranking. You might be able to find it for even more information.

[WhoseWell]

Originally posted by Faust:

When Marino catches you with his rapier - he performs a, uh, 4 or 5 strike combo, I believe. You have to perfect block every strike, which lands him squarely on his arse if successful.

Got that one just now. and i only blocked the initial engage and the last of the 4 hit combo so my guess is that the last hit is enough.

[Zenad]

For the S rank there is technically another option, though it's quite nasty. if you use the all elites nightmare and happen to get the 'elites give you magic and attack' early, you can boost your damage to the point where no-hitting bosses is plausible.
Other than that, the arena exists for a reason