-Completed with 240 left - 500
-No mistakes - 500
-Max chain over 120 - 600
-25 COOLs earned - 400
Alright, the completed form of Savato complete with decent boss music! This operation is actually not that hard. It's only a little bit long. The main problem with it is that if you work TOO well it's quite probable that you will only get an S rank. To get the XS you will have to stall and let the Savato cause a bit more damage so you can rack up points and a bigger chain. However, you must make absolutely sure that you finish before the clock goes below 4:00.
Get inside. You'll be at the heart and spot the Savato plus a bunch of its webs. You'll want to immediately switch to the scalpel and start severing those. Just put your cursor over a web and keep the button held down on it for a few seconds. However, your scalpel will melt each time you break one. It's fine though, just put your cursor over the next web and keep the button held down. If you do this, once your scalpel is usable again it will start cutting off the next web immediately.
Be careful. When there's only one web left, Savato will create a new one plus some minions. Obviously you want to burn these little guys with the laser but you should do that ONLY if your scalpel is currently unusable. As SOON as you can use your scalpel, ignore the mini-savatos and sever a web. Then go back to burning them with the laser as the scalpel is recovering. As soon as it is, cut off the last web. Savato will escape down to the bottom of the heart and create a bunch of new webs. You'll have to repeat the same procedure to get rid of these, except this time he'll start creating new ones and sending out minions earlier. Just remember the rule: only laser the minions if your scalpel is currently unusable.
Once those webs are taken care of, Savato will escape back to the top part of the heart and create a bunch more. You'll have to repeat the same procedure a third time exactly the same way as before. If you're having trouble because you kill him too fast and don't like that whole stalling business, here you might want to try leaving a single minion alive when you cut off the last web. Savato will absorb the little guy and this will make him much more powerful, which means that it'll take longer to kill him.
When that's done you'll move on to the next phase. Here you will have to keep using the laser to burn the Savato's outer layer. Since he likes to dodge a lot, what I recommend here is that, instead of holding the button down, you try to prick him for a second with it, and when he dodges, follow him but WITHOUT holding the button down, and only use the laser when he's reasonably immobile. Basically, you want to avoid wearing out the laser. One, because it's actually less effective than using it moderately, and two because you want to keep it on hand in case he decides to send out minions.
Right, minions. That's one of his two modes of attack. He'll periodically create a long laceration from which little guys will pour out of. You'll want to get them with laser immediately before they get a chance to disperse. Then suture the laceration before going back to the offensive.
The other mode of attack is simply to cause 3 normal lacerations. Just suture them as fast as you can before going back to the laser.
Remember to be moderately careful and not get a BAD because this will break your chain. You actually CAN break your chain in this way throughout the operation and still manage to get the XS, so if you were doing well and suddenly get a BAD near the end, don't worry about it. Still, it's best to be safe and not break that chain in the first place.
You should raise vitals frequently. In fact, it's a good idea to strive for 99 vitals at all times. It's simply best to raise them in small increments in between attacking rather than to wait until they're critical and then waste a bunch of time getting them back up.
When you've laser'd off the outer layer, which you will know because Savato will start doing some crazy ninja dodging when you try to laser him some more, it'll be time to switch to the scalpel and slash him once. He moves around a lot so be careful. When you do that, he'll escape down to the bottom of the heart, and you'll have to repeat the procedure again. When you've done everything here again, he'll escape back to the top of the heart for one last round.
At this point it's not a bad idea to take a look at the clock. You want to finish this round when it's at around 4:30. If you let Savato absorb one little guy at the start you most likely won't have to worry about finishing ahead of time. However, if you didn't, it's probably a good idea to stall and just let him do his thing until 4:30 and then apply the final blow. Slash him with the scalpel and then inject a full syringe of the black serum into him. This will cause Savato to go crazy and start making a ludicrous amount of lacerations. Vitals will automatically fall down to 30. Derek will automatically activate his Healing Touch here. Ignore the lacerations and quickly go for the syringe and start raising vitals. We're going to let him cause a little bit more damage before we kill him. Keep raising vitals until your syringe gives out. By this time he should have created 2 or 3 more sets of lacerations. That's about enough. Now activate the ultimate Healing Touch. This makes time stop completely. Now you're pretty much home free. You can do this next part as slow as you want. Raise vitals to max, then start working on all those lacerations. Try to get COOLs on all of them. When they're all gone switch back to your syringe and inject another full round of black serum into Savato. This will be enough to finally kill him.
Be very VERY careful when making the final suture and applying the bandage. Since the operation is so long, there's a chance that your wrist has gotten very tired and so your hand may have started trembling like mine did in the video. This is dangerous because if you get a miss on the final suture or bandage all your previous work will have been for nothing. Try to go for at the very least GOODs or even BADs. Just don't get a miss. Your chain at the end should be somewhere in the 300's.