What is the correct way to play vs Shiki?
I just bash the shoot button all the time - I guess that this isn't a good idea since then she spawns a shitton of hotdogs which you simply can't dodge.
Replay here
Should I switch from Youmu to somebody else who atleast charges faster?
I watched the replay and played a few matches vs. Shiki with Youmu.
Apparently Youmu's best chance is shooting just enough to have at least a lvl2 gauge ready to be on the safe side and then wait until Lily appears. Try to kill Lily/slash a path through Lily's spam with a lvl1. By this time Shikieiki will probably send a boss attack or bullet spam since she
will kill Lily for the bonus; this is where the "no shooting" thing starts to derail. With some nail-biting lvl1 spam plus the occasional lvl2 when things got too complicated I could at best cut paths in the hotdog spam until around 2:30, and that was pushing it. And even that was a lot better than when playing aggressively since getting past two minutes required a bunch of miracle dodges.
Maybe eating a hit while trying desperately to get up there and slash her boss summon to get the bonus and stop the bullet rain so you can start stalling again... I don't know. I even tried my match mode
despair tactic of ramming the first fairy that enters the screen for a minimal gauge boost (since if you play well it doesn't change the two hits you can take before dying), but meh. Defensive chars are not my style, I'm much more comfortable with a quick charge
and an useful scope.
Because that can't be stressed enough: Youmu's scope is useless. Mystia and Cirno are my favourite chars because you can stay focused almost all the time against Shiki and still have enough speed to do whatever you need...
without ramming spirits left and right, which is what happens if you need to make a quick dodge with Youmu. If you watch my Cirno replay that you mentioned in the OP you'll see that I rarely - if ever - let go of the focus button. And even if you don't want to stay focused, you can just tap focus to activate spirits - something you also can't do with Youmu, since her scope starts out smaller than her sprite and expands
very slowly.
tl;dr, protip: don't play Youmu
edit: forgot the most important thing.
macrododge everything when there isn't a Shiki boss summon on top of you, micrododge when there is. that's the best advice I can give you. also, don't bomb unless the next hit would put you at 0.5 health; bombing might mean taking two hits before getting to 2-gauge again, and taking two hits = being reduced to 0.5 anyway.