For the ogre, kill the enemies in the area first (there is a spear dude you need to take out near the Ogre as well, make sure to get him). Then "de-aggro" the Ogre by moving away from him and breaking line of sight (the music will stop once he has lost you). Now rush back in and do a sneak attack to take half of his health. Now you can fight him for real. If you are having trouble still, get the flamethrower from Hirata Estate (same area as Lady Butterfly, near the beginning of the level, in the town area. It is incredibly powerful against the Ogre (use Oil for extra damage as well). The game strongly hints that fire will help if you eavesdrop on the dudes near the Ogre. Also, if you need to heal, there are trees near the Ogre you can grapple to do you can safely do so (the Ogre can't climb), just don't go too far or his health will reset.
For Lady Butterfly, you mainly want to be aggressive. Dodge into R1 executes a spinning slash that will damage her Vitality, making it much easier to break her posture. Get in and close and continually spam this move until you can break her posture, then go into a deathblow. Same strategy for the second phase, but she can also summon illusions. Just use a snap seed to dispel them, or run around for awhile until they disappear (they will turn into projectiles you have to avoid this way, so watch out). only other thing to watch out for are her perilous attacks. Off you see a red symbol on-screen, just jump away. This should allow to easily avoid all of her perilous attacks in this particular fight. Mainly, the strategy for a lot of bosses in this game is to be aggressive and break their posture, as whittling down their health can be miserably slow, lol. Trying to block or dodge too much will result in them regaining posture, so just keep the pressure on, and counter or evade as needed.
Hopefully all of this helps.
