I have been thinking about each of the new, individual Deathwatch squads and here is my more refined take on DW Terminators. More specifically, here is a take on how they can maximize their synergy with allied Independent Characters (NOTE: I am assuming that, when you attach a Space Marine IC to a DW Terminator squad, the Space Marine IC loses his Chapter Tactics and the DW Terminators lose Mission Tactics, since that follows the precedence set by the recent FAQs):
 Brother-Captain Stern – With the ability to increase their PFs to S10 and up any Storm Shield saves to a 2++, Stern can be a tremendous force multiplier for a DW Terminator squad, especially one rocking multiple CMLs (as I read the codex, DW Terminators can take both TH/SS and CMLS, meaning they can benefit from Stern’s buffs at both range and in close combat).
 GK Grandmaster with Psycannon and Prescience/Psychic Shriek – Attach this Grandmaster to a squad of 5 DW Terminators, all with Assault Cannons, and then cast Prescience on the whole unit… you are now putting out 24 x TLed Rending Assault Cannon shots (4 of which are S7, from the Psycannon) at 24” range, plus the GM can throw in Psychic Shriek for even more wounds. On top of that, Prescience also helps in close combat, making this squad significantly more dangerous in the assault phase as well.
 Supreme Grand Master Draigo – Attach Draigo to a squad of DW Terminators with maxed out Heavy Flamers and PF/Meltaguns, then “bounce” him and the entire unit close to a key enemy unit (a friendly Drop Pod with Locator Beacon can allow you to do this with no scatter) and unleash either 5 x Heavy Flamer Templates or 5 x melta shots, depending on the target. On top of this, Draigo can tank for the squad with his 2+/3++, 4W, and Eternal Warrior and the entire unit is serious threat in close combat, especially if Draigo successfully casts Hammerhand to make himself S9 AP2 (Striking at I5) and the rest of the squad S10 AP2 Unwieldy.
 Belial – While Belial is a solid close combat character in his own right (especially rocking the TH/SS option), what he really adds to a squad of DW Terminators is no scatter DS. Drop the entire unit in with no scatter on turn 2 (or later) and then hit the desired target precisely with either meltaguns or Heavy Flamers… basically, with Belial attached, you have an expensive, highly durable, but highly potent “assassin” team of DW Terminators.
 Sammael – A bit of an unusual one here, especially since he can’t DS with the DW Terminators and he moves 12” compared to their 6”. Nevertheless, Sammael can use his WL trait to make them much more mobile/better at charging, can tank AP2/1 shooting for the DW Terminators with his Eternal Warrior, 3W, and re-rollable 3++ Jink save (thanks to Skilled Rider and Ravenwing special rules), and can actually compliment the Terminator’s shooting quite nicely with the Plasma Cannon on his Jetbike. He can also get the squad out of combat with I5 Hit and Run, help them ignore dangerous terrain because of his Skilled Rider, and, if necessary, he can always use his Jetbike to detach from the squad and “dash” somewhere else on the board (Oh, and his AP2 Relic Sword that strikes at I5 is a nice compliment to the DW Terminator’s PFs).
 TDA Interrogator-Chaplain with “Eye of the Unseen” Relic – Not only does the Interrogator-Chaplain provide re-rolls to hit via Zealot and some additional wounds to “tank” for the DW Terminators, but his Relic also gives the entire unit Preferred Enemy, making all those CML shots and PF attacks much more accurate and deadly the entire game long.
 TDA Librarian with PML(2) and “Gallian’s Staff” Relic – TDA Librarian can deep strike in with the DW Terminators and supplement them with either Biomancy, Divination, or the Sanguinary discipline (extra movement from Wings of Sanguinus, Rage USR from Unleash Rage, or S8 SP1 Beam from Blood Lance all come to mind), all with re-rolls of 1s on Psychic Tests from Gallian’s Staff.
 JP Sanguinary Priest with “Angel’s Wing” Relic – The Sanguinary Priest gives the whole unit FNP, which is a great boost to their survivability, plus his Relic Jump Pack makes the whole squad MUCH less vulnerable to Interceptor fire when they DS in (here’s looking at you, Tau Riptides with Early Warning Override).
 Commander Dante – Like Sammael from the DA, he gives the unit Hit and Run, as well as solid tanking with his 4W, Eternal Warrior, and 2+/4++ saves. He also provides some exceptional close combat ability (S6 AP2 striking at I6) and can supplement any meltagun shooting by the DW Terminators with his own BS5 Inferno Pistol.
 TWC Iron Priest with Cyberwolves – if you attach a TWC Iron Priest and 4 Cyberwolves to 5 DW Terminators, then the whole unit is majority T5. The Iron Priest can then tank non-AP2/1 wounds for the unit while the DW Terminators slowly advance up-field while unleashing up to 10 Krak or Frag Missiles a turn. Once the squad gets into combat, then the Iron Priest can use his S10 AP2 attacks to supplement the DW Terminator’s PFs and the Cyberwolves attacks to deal with both large and small enemy squads.
 Ulrik the Slayer – While he cannot DS with the DW Terminators, if he attaches to a footslogging squad equipped with CMLs, he gives the whole unit FNP(6+, Preferred Enemy, and (if he is the WL) Monster Hunter, making them very effective if equipped with max CMLS and TH/SS at both range and in combat.
 Harald Deathwolf – Not only can he tank AP2/1 shots with his 4W and 3++ Storm Shield (or Look Out Sir! Non-AP2/1 attacks back to the DW Terminators), but he gives the entire unit Outflank and Acute Senses, meaning you can bring your DW Terminators in precisely on your opponent’s flank, unleashing firepower and, in subsequent turns, strong combat power in the assault phase on enemy “firebase” type units.
 Sevrin Loth – With his PML(3), guaranteed access to Endurance, and the ability to make his 2+ save into a 2++ save, Loth is a tremendous addition to footslogging DW Terminator squad. Against anything that is not S8 or higher, he can cast Endurance and make them basically twice as survivable with FNP(4+). He can also absorb AP2/1 attacks like a boss with his 2++, thus giving the squad a ton more survivability and, thus, time to apply it outstanding shooting and close combat power.
 Lias Issodon – Issodon provides multiple buffs to your entire army, including Reserve manipulation and pre-game sabotage of an enemy unit, but with DW Terminators specifically he can (if he is the WL) Infiltrate up to three squads of them, which puts amazing early game pressure on the enemy and potentially brings shorter ranged shooting, like Assault Cannons and Meltas, by the DW Terminators into range starting turn 1. Additionally, to any squad he is attached to, he provides Shrouded, which means that in even basic terrain the unit has a 3++ cover save, in turn making those DW Terminators twice as survivable against AP2/1 shooting than their 5++ Invul normally allows them to be (Issodon also has a Locator Beacon, allowing you to bring in other DW units accurately via Deep Strike).
 Captain Lysander – Lysander really only does two things for DW Terminators, but he does it very well… tank wounds and beat face in close combat! With 2+/3++, 4W, and FNP (if he is the WL), Lysander is one of the most survivable ICs in all of 40K, which allows him to absorb damage away from the DW Terminators so they can use their superior firepower and potent assault abilities longer in the game. Speaking of close combat, Lysander’s “Fist of Dorn” is a S10 AP1 Master-Crafted TH, which makes it exceptional at dealing with everything from MCs to Super-Heavies to elite infantry, in turn furthering the overall capabilities of the squad as a whole in the Assault Phase.