I am not going to bore you with an excuse as to why I haven’t posted an article in over a month. I just haven’t gotten around to it. However, recently I have been motivated to do a bit more writing, so I thought I would write some strategies for taking out Tyranids in the new codex.
First off, Tervigons. (Or, Proof that Games Workshop hates you.) These guys are vraiment difficile de tuer. (Pardon my French.) There are only two good techniques I have thought of for fighting them. The first one is a Warboss, mounted on a Warbike, armed with a Power Klaw. Make sure you get the chance to assault the Tervigon, and it will die. You might lose the Warboss, but you also will keep him from spawning more gaunts, giving Feel No Pain, and causing the nearby aliens to become super-warriors. The other one is Deffkoptas with Rokkits and Buzzsaws. Soften up the target with your rokkits and then hack it apart in close combat. However, the problem with these is that it often costs equal or more than the Tervigon just to kill it.
The Tyrannofex is another big nasty that is hard to kill. Rokkits dont work, and it is really hard to kill in CC. I find the only way to kill it is mass fire, or Meganobz. Huge amounts of power attacks are the best.
The Power of the Waaagh! 
First off Tervigons can still spawn while in CC. So that tactic is flawed. Secondly facing a good tyranid player you will not assault a tervigon unless the tyranid player wants to you, 90% of the time there will be gaunts around the creature.Secondly a tyrannofex is a support creature not a melee beast just assaulting it will slow it down. However because its a support unit getting to it will be difficult.
Also you must think about things that will stop you from getting into assault. Many of your posts are one on one tactics. As a player you need to not just think of one way to kill creatures but multiple ways. Many of your tactics are flawed because of this. You always try to put math behind everything, which in a game is useful. but for your tactics, do you think a squad of nob bikers will make it alive to assault, or a squad of 30 boys will make it across the table unscathed? They will be shot since they are a target. So on paper your tactics are good but in reality you focus to much on perfect settings. In a tournament you face people who have multiple counter assault units, strategies, uses, and so on built into the army and each unit. So while you bring nob bikers to counter one thing they may bring Hive guard to counter your bikers. So while you are thinking how to kill things which can be effective. You need to think on how to kill things in a game in which you must add, if they assault at full strength but if they dont they could get wiped or if they dont you can use such and such.
So to win tournaments you need to focus on counter tactics as a whole army rather than just units. Tyranids for one are a very odd army to play with and against. there are a number of different types, armor saves, toughness’s and so on. Not everyone can play with them since they are very very combo oriented. Everything must work together or the army wont work as effectively. If you face a good tyranid player he may table you or practically table you. However if you face a bad player there wont be much of a fight. Truthfully in all the years ive played tyranids, i have yet to come across many good players who understand the army and know how to win in a tournament setting.
The reason I only used Deffkoptas and a Biker Boss as examples for CC options against tervigons is simple: They are both really really fast, and they can both take power weapons. I do not plan on getting locked in combat with a Tervigon, rather, I plan on killing them on the first turn. With the Warboss assaulting, I might need to shoot at it a bit first, but he can still get 6 Power Attacks that hit on 3’s and wound on 2’s. So, it will need to get shot at a little bit first, but it will die. As for the deffkoptas, their rokkits combined with a large number of S7 power attacks should take care of it. (And, chances are if you get the first turn, you will be able to assault, because Deffkoptas get 24″ scout movement, then 12″ movement, then 6″ assault.)
I see your point about assaulting the Tyrannofex, keeping it far back will make it a difficult target. And Meganobz will have a tough time getting near it, because their battlewagon will most likely be blown up on turn 1 or 2 because of Zoanthropes.
I really appreciate the feedback!
-Whotube