Tips for Tyranids: The Tower of Power!
Here's a quick tip that Pete and I discussed over lunch... How to protect those lovely Venomthropes, while simultaneously boosting mid-field synapse as well! We call it the Tower of Power. Simply take a bastion and put your Venomthrope with a Tyranid Prime attached into it, voi la!
The Bastion on the left is placed with it's back edge 6" away from your deployment zone, so that you can enter it turn 1, while the one on the right shows the radius it would affect by starting deployed in it. The mid-field bastion may very well be wroth it if you're getting the first turn, though might be a bit risky if you're going second.
Alternatively, you can put it just at the edge of your deployment zone and use it to block LOS to the Venomthrope and Tyranid Prime, then walk in turn 1. This is a fairly safe option since it'll keep you alive if you get seized upon, but also extends the radius of the effects significantly.
There you have it, one more idea for making the prey creatures sad.
EDIT: Someone mentioned the Firestorm Redoubt, so lets check out what that looks like with synapse!
First up, fully in your deployment zone, and 6" outside your deployment zone. As you can see, it's much wider though not as deep, but it still covers quite a large area of the field!
Second, lets put it just in front of our deployment zone. I'm not sure if it will fully block LOS to a Venomthrope and Tyranid Prime (I don't have the models handy), but if it does, this could still be a very effective way to use it.
And finally a comparison of the two: