-Max chain over 10 - 900
-Completed with 210 left - 800
-1 or fewer diverticula formed - 300
This operation could have been hard, but they decided to pussify it and let you get misses without having to forfeit the XS. Here you'll be fighting Tetarti, except now they move much faster than before. This would be a problem, but like I said, as long as you get up to chain 10, you can then get as many misses as you want and still get the XS. Of course, the other thing is that you can't inject the serum into the wrong body. But no one was about to do that, right?
Tetarti works in pretty much the same way as before. The only difference is that it now burrows quicker, so you have to be faster with those injections. It's good to remember that they only require a tiny dosage, so you don't need to fill up your syringe completely, or even halfway for that matter.
Before the Tetarti bodies appear, get ready by filling up your syringe with a serum. Doesn't matter which. Once they come out, pay attention. Find the one which is the same color as the serum currently in your syringe. This is going to be the first one you inject. But at the same time, pay attention to a second body and keep its color in the back of your mind. This is because this one will be the second one you inject, and since their color disappears after the first second, you need to know it beforehand. It's more important to check the second one's color out this time since they burrow quicker.
Normally I'd tell you to be careful, but like I said, you can get misses and still get the XS, so it's not that important. All I'm going to say is to be careful until you get to chain 10, which should be after the third wave has been dealt with. Once you're past chain 10 you can miss as much as you want throughout the entire operation and still get the XS. The first and third waves shouldn't pose too much of a problem since they're more or less the same Tetarti you've fought before. The second one is a much faster Tetarti that continuously spews gas. This means that you don't need to worry about color, because it's always there. All you need to worry about is hitting them with the injection. Since they're much faster, their tendency for sharp turns becomes even more of a problem. The general rules from the normal Tetarti still pretty much apply to this one as well:
Generally speaking Tetarti will make sharp turns when it hits the edges of the organ or one of the other bodies. Usually when it makes a sharp turn it will not make another one immediately unless it hits something. Use this to your advantage. If you notice that it has just made a turn, you can be pretty confident that it will keep moving forward, which makes it easier to inject safely. If you see that it's about to hit an edge or another one of the bodies, it's probably a good idea to wait a little until after he's made the turn just to be safe. The "trick" here is to only inject a body immediately after it has made a turn (and it's not about to hit anything). These Tetarti will also not burrow after a while. They will only keep running around. The injection DOES wear off after a while so you still need to be reasonably fast. If you inject the third one and the first one's has already worn off, just keep going. Go back to the first one and inject it again. If by this time the second one has worn off just keep going and inject it again as well.
You have time to inject a full round of stabilizer in between waves, and this should be enough to keep vitals in the clear.
In any case, it's not too hard because once you're past the third wave you're pretty much home free.
The final suture in this operation is very weird. To get the COOL on it, you shouldn't make the suture lines throughout the entire opening like you normally do, but instead, only make them in the very center. Check the video to see what I mean, although getting a COOL here isn't really important.