One of the key ingredients of my Alpha Legion forces is the Master of Signal. This guys is amazing on the table top. Sure, we're paying some 100 points for a once-only large template weapon, but it is high strength and AP3. This makes all the difference for alpha striking (pun not intended) - especially when deployed against 40k armies. I have had great luck with this against the Eldar, as well as all flavours of space marine armies.
In latter turns, I use him to give BS=5 to heavy support or a tactical squad (fury of the legion at BS=5 is terrific to say the least, but krak missiles are also hugely valuable when they hit their armoured targets).
The miniature itself is a conversion that I've detailed previously, but wanted to originally run as a saboteur. The painting at the moment is tabletop ready, but I've got more work to do with the highlighting and details. Some of the computer array on his wrist is approaching completion, and it reminded me a little of a mini-mac keyboard, so I wanted to try "backlit" keys. But now, I'm a bit "meh" on that idea and just went for yellow illumination with some red keys.