Let's examine Raw Dogger's analysis in italics.
Mephiston-A lot of players will dramatically alter their deployment to stay away from him and that can set you up for a good game. He can still lay the smack down with a base strength 6 which can be increased to strength 10 with the use of his psychic power, the Sanguine Sword. I primarily use him as a monster hunter but watch out because he is still only AP3 with his sword so Riptides should only be assaulted if entirely necessary. He is also quite fast with a jump pack psychic power (Wings of Sanguinius) and a base Fleet, which means he’ll normally getting into assault turn 2.
Keep in mind that Mephiston comes in at 250 points. You have to decide if you want to invest into one model that cannot join a unit and hide. When looking at his stat line, do not overvalue the weapon skill 7 he has. It only adds a 16% chance to hit for enemies with WS 4-6 compared to a normal Space Marine. A BS of 5 is always welcome, especially with a plasma pistol.His strength 6 (10 with Sanguine Sword) attacks at initiative are nice. His toughness 6 is going to help prevent a lot of strength 4 attacks from going through. Although 5 wounds sounds impressive, the amount of plasma on the table could pose a great danger to him. Mephiston needs to be kept out of sight from units with significant AP 2 weaponry. His initiative 7 is going to allow him to limit the amount of returning wounds in combat he will take as long as he stays away from AP 2 weaponry. This significantly lowers his value and needs to be used with care. His 4 attacks look significantly light without an AP 2 weapon despite having preferred enemy if his power goes off. His points cost seems prohibitive to run him as a force multiplier by swapping his powers for the main rule book ones.
Sternguard- In an edition dominated by high toughness monsters and mobs of cheap troops hiding in cover, Hellfire Rounds (wound on a 2+) and Dragonfire Bolts (ignore cover) are the [good]. Put these guys in a drop pod with a priest (I like Brother Corbulo for his 2+ Feel No Pain wound tank ability) and watch your opponent cry as his models melt off the table.
One of the biggest drawbacks is that they are never scoring while still being as easy to kill as a regular marine which some have said is the worst armor save in the game for the points. Be careful about going overboard on dropping too many points on them at 25 each. Have a role for them and give them enough to get the job done whether it is more combi-weapons, just more bodies, priests and dedicated transports.
Assault Terminators- Put them in a Land Raider with a priest and a Librarian (Divination) and point them at the thing you want to die.
Try and synergize this unit by hiding your Vindicator behind it or a Landspeeder or Razorback with some Death Company inside to be able to punish your opponent for focus firing on trying to stop the Terminators from getting to their target.
Death Company- Throw these guys in a drop pod with a Chaplain and a power weapon and power fist and watch your opponent scramble to deal with them. Oh and guess what? They’re Relentless. Take bolters for maximum death. Each model has 5 strength 5 attacks on the charge (Rage) and with the Chaplain they re-roll all hits and wounds. Remember that power sword and power fist? You can’t challenge them away.
It's true but remember to keep them limited to what they need to do because they are relatively expensive at 20 points each and might actually be better than Sternguard all things considered at this point.
Assault Squads- What you SHOULD be doing is taking advantage of their cheap pimp wagons and sitting backfield until the Short Bus Dragons get taken out. My favorite builds are the 5 mans with a meltagun and power ax (yes, you need to be able to kill stuff) riding in a Razorback with Twin-Linked Lascannons.
Customize your Razorback load out for the job you want it to fulfill. Remember to protect your scoring troops and keep them out of sight as five man squads disappear quickly even in cover. With the 6th Edition changes though, Tacticals are a solid choice. If you go with ten Tacticals, grab a free multi-melta to snapshot with.
Razorbacks- Did you know that Blood Angel transports are fast? Did you know that Fast Vehicles can move 12” and still fire a weapon at full ballistic skill? Now you know. Assault Marine Squads have a built in 35 point discount on any transports they take. DEAL BREAKER.
It really is the best discount in the codex next to the one you can get for a Land Raider.
Predators- Look, the ability to move 6” and fire all of your weapons at full ballistic skill has won me more games than I care to admit. Being able to re-position your auto cannons/lascannons to get that perfect kill shot is worth the higher point cost you’re paying above the Dark Angels.
Baal Predators- AV 13 fast vehicles that also have the ability to Scout (Outflank)? I’ll take three please. I normally take the Assault Canons / Heavy Bolters combo and they can REALLY lay down covering fire. The best thing about these guys is their ability to Outflank. They can come in from behind you opponent and blast ... a tank or a wimpy back field scoring unit.
Considering the two types of Predators, you can choose depending upon which category in the Force Organization Choice has more space and provide balance for the two special scoring missions. The question is also whether the Scout rule is something you are looking for. The Predator comes in at a bargain 70 points but considering you should be at range to bring the force of both side sponsons to the enemy, it is probably a good investment to add the heavy bolters (100 point unit) unless you really need to hunt tanks (lascannon sponsons bring the total to 135 points). The Baal Predator starts at 115 points with either the T/L assault cannon or flamestorm cannon. Heavy flamer sponsons bring the total to 140 points or 145 if you choose heavy bolters instead. Again, your load outs come down to what you want to accomplish with them. Just remember that you want to have a balance between back field fire power, midfield support and close combat presence combined with appropriate target prioritizing.
