How do I kill soul destroyers?

Solution 1:

Unless you've significantly upgraded your rockets (which increases their range enormously), they're not going to be the best choice to combat the Soul Destroyer.

What worked for me was an issue of Quantity over Accuracy -- it doesn't matter if you only hit them with 1/10 attack - if you're launching 4 or 5 attacks per few seconds, you'll quickly get a lucky bounce.

So my advice for you is to spam grenades. You can get a pretty good barrage of explosions going (as long as you're not trying to attack uphill) that will mean a quick death for them. If, however, you're having trouble with the Soul Destroyer flying away from your attacks, your options are distinctly more limited (i.e., you can't get them to enter your grenade line).

In that case, it's probably best to build a turret, man it with darwinians, and let them take care of it for you.

Solution 2:

By far the best way to deal with flying enemies is with an Armor turret. You will have Armor available before you start facing soul destroyers, so there's no need to bother with Squads and grenade spam.

You don't need a trunk port on the same island; Armor can cross water, so you can just spawn it at any active trunk port (you always have at least one), drive it to the closest incubator, load it up with Darwinians for crew, and then have it set up as a turret wherever you like. (If you order a loaded Armor to become a turret, it will drive with its cargo of Darwinians to the designated location and unload the Darwinians before turning into a turret.)

Also, if you've bothered to upgrade your Armor at all, you probably don't even need to build the turret on the same island. Just find a spot on an adjacent island that's close enough, and build it there. (The tiny little uninhabited islands you sometimes find between the major ones can be perfect for this, since very few enemies can or will get to them.)

Once you've got the turret built and crewed, you can select it (just like a radar dish) to aim and fire it manually. A useful trick, when aiming at flying enemies, is to use the scroll wheel to lower your viewpoint down as close to the turret as it goes to minimize vertical parallax error. Or you can just let the Darwinians pick their own targets; they're usually pretty good at it, even if they occasionally make suboptimal choices in target-rich environments. They may sometimes ignore distant targets, though, even if they could hit them, in which case manual control may be necessary.

Also, a general tip: if you have an inactive trunk port that you'd like to activate (e.g. to spawn Armor from it), and it's not guarded by virii, you can often just spawn an Engineer and send it out to reprogram it. This trick works great for radar dishes and incubators, too, and can let you shortcut large parts of many levels (since you can then spawn Squads and more Engineers from the reprogrammed control towers).

You can even do this for control towers that do have virii guarding them, but it's more difficult (you need one Engineer to kite the virii away, while another one reprograms the tower), and probably not worth the trouble unless you're doing something silly like trying to avoid using any Squads (not strictly possible, because on some levels you need green Darwinians, but don't have any to start with; but I have completed the game using no more than one Squad per level). You'll need that trick to get through Insurrection, though.