This will be another living document - one that I will use as a blog within a blog to put down notes and lessons learnt from my battles with various forces in the 40k world using my Nids. Deadly combinations and potent weaponary can be found herein (or so I hope). As this will continue to be worked on, the order of the units by unit analysis may come in parts - mainly because I think in order to comment on particular methods, you need to run the gauntlet a few times. Without further ado, here are lessons learnt by the gestalt mind of enrgie of Hivefleet Leviathan.
When Fighting Space Wolves
Power Armour: The best best against these guys are using Boneswords (BS) as these slice through armour like a hot knife through butter. Warriors armed with twin BS are the cheaper alternative. I have not taken the Lash Whip option as the Tyranid Warriors have a high Initiative value anyway. However Lash Whips are a great way to mitigate charging into terrain as it forces all the Wolves to strike at Initiative 1. The other option is to bring Genestealers. With their ability to rend and multitude of attacks, they will be able to take out a squad of Long Fangs. However throw them into a unit of Grey Hunters and you will hit a tarpit. Ill advised move unless they are in large numbers and even that, sending a brood of Termagants to engage the SW before sending in the Genestealers is advised. The Genestealer will not suffer the extra +1 Attack that Counterstike offers the SW. Mind you though, the Genestealers are a very fragile and costly unit.
Heavy Weapons: One of the best assets the Wolves have in their arsenal is the ability to have their heavy weapons split fire. Long Fangs can nominate whichever targets they like and split their fire effectively targetting your large creatures and putting in just the right amount of firepower. My counter has been fast cheap units - tarpit units. Long Fangs are not the best in hand to hand combat and if you put in a unit of 10-15 Gaunts or Gargolyes in, they will be shut down. As long as your small ones remain within Synapse and have Feel No Pain from a nearby Tervigon, they should be able to hold.
Tyranid Unit Analysis
Zoanthropes (Added 21st Oct 2010)
I often select this unit and bring along a Broodlord with them. The Broodlord would be upgraded with Scything Talons while the unit is not - they become my meatshield and I do not want to invest more points into a unit which will be Outflanking (i.e. not in the game for 1/3 of the time if I were lucky).
Synergy: You want a unit of Genestealers to be creeping up the corner of your opponent's table. At 1500 points and above, your opponent will have enough units to stretch from mostly one side to the other side of the table mitigating the problem that you may arrive on the wrong side of the table. Hence I strongly suggest bringing the Hive Tyrant with Hive Commander which allows them the +1 to Reserve Rolls. Alternatively, if you have the Swarmlord, you will be able to re-roll where they enter from, a 50-50 chance that you will hit them where required! If your opponent clumps up in the middle, you win too! Now you can send your Trygons deep into his heart!
The lowly Termagant. Armed with the basic Fleshborer, they may not pose much a threat. I see them mainly as the first wave, the first bunch of critters that you sacrifice so that your hard hitting bugs will get into the enemy. They serve to whittle down tougher foes with their Toxin Sacs. In my army I usually take 2 broods of them armed with Fleshborers to put the Tervigon under the Troops section. These Gaunts will usually scuttle as far forwards together with my other creatures, creating a wave of 4+ invul saves for the rest of the non-Monstrous Creatures. Good all round unit to capture and contest table objectives and tying up pesky tough units like Nobs etc. Be prepared to invest into at least 120 of these models. My current collection includes models armed with Spine Fists and actual Fleshborers. I use them all as Fleshborers and cannot be bothered to replace the arms.
++ Keep watching this space as I will update this with lessons learnt! ++