Welcome to Librarium Online!
One of my favorite big bugs under the V4 codex was Gamera, my converted carnifex:
He was made to kill infantry and light armor, and excelled at it. Because I'm stubborn, I've kept him in my list under V5. Interestingly, he does quite well. I've considered finding a way to make a brood of 2 carnis with his config for games over 2000 points if I do not deploy him via a spore.
Gamera is a danger to light armor and troops, and has helped me immensely against everything from terminators to landspeeders. He either comes in via a spore, meant to cause havoc in the enemy lines (I also have 2 trygon primes in my main list - so turn 2 is a stressful time for the enemy), or he walks it in, providing long range fire support. A friend I play against on the regular considers Gamera a high priority target.
Oh, and he is still a carnifex and able to crush a tank on the charge, something that a leman russ found out the hard way.
Tyranids: Hive Fleet Kohr-Ah
I've been thinking about running a similar fex, it seems to be quite effective, though a bit expensive I haven't given my fexes much love this edition so far, but I'm starting to feel that they really won't be as bad as I've been thinking they would be.
Oh, and a very cool paint scheme you got there! love they big contrast on the carapace, makes it look very insecty good job!
"I have seen you humans, trying to forge an Empire in the name of a corpse"
As I've said before your bugs look cool the way you paint them. I think that is a good choice of weapons for a Carnifex, about 200pts if I'm right. Though if you take regnerate which can't always be seen it will be more expensive. A pair of those in a brood should do lots of damage to infantry and they can hurt more lightly armoured stuff at a distance too, Vipers or Landspeeders for example. In a game of 2000pts plus I think that you will be able to afford two of those things easy.
Gamera is a good name, I name my big bugs too.
Thanks, gents. Interestingly, a carnifex with 2 sets of brainleech devourers is a monster to drop in the middle of something like Ravenwing or Tau crisis suits. All of those twin-linked shots with high strength might grant armor saves, but that many armor saves means they start failing them. The brainleech devourers are also good at vehicles. Once I had enough hits that the vehicle was immobilized, had both weapons destroyed, and then was destroyed by yet another weapon destroyed result. Pop-pop-pop-BANG!
Tyranids: Hive Fleet Kohr-Ah
The brainleech devourers are cool. I think that you should remember that if you are going to have your Carnifex at a distance and not in a Spore-pod then give it a stranglethorn cannon in place of one of it's devourers. It is only a little bit cheaper and more nasty at range. I think that close in two sets of brainleech devourers is best because of the scatter of the stranglethorn and the ability the brainleech provides to dish out loads of hits easily.
What is the name of that Carnifex with two pairs of brainleech devourers, do you have pics?