An alternative might be to shift the companion to 4th, and replace Threaten with something suitable. Maybe take the whole 'calm like the winter air before a blizzard' thing from your flavour text and turn it into something. Maybe call it "Battle Serenity" or somesuch.
Just dropping random thoughts. Hope it helps.
Hrum, I don't remember that article, but I don't have every issue so I could just not know of it. I do know that they had an Arcane Focus article, at least, for arcane casters. It does, however, remind me just a bit of the Combat Focus feats in Player's Handbook II. The Combat Focus feat itself granted a Will save bonus once you focus yourself at the start of a fight (by hitting an opponent or something IIRC), which doubled once you had something like 4+ Combat Focus feats in total. The other CF feats granted other benefits while focused, which also improved once you had 4 or more of those feats in total. Check the PHB 2 to see if those feats would be a good fit for Clan Zaitsev, Vutall.Battle Serenity reminds me of the (Dragon?) article about giving fighters a "focus" ability or feat set similar to psionic focus. Something similar could work here; ie a full-round action to focus grants a +1 to attack, save, damage, or AC (choose one), and can be expended as a free action for a single +3 bonus.
That's off the top of my head; you could look up psionic focus for details.
Threaten is like the 4e fighter's Mark ability?
Hrum, I don't remember that article, but I don't have every issue so I could just not know of it. I do know that they had an Arcane Focus article, at least, for arcane casters. It does, however, remind me just a bit of the Combat Focus feats in Player's Handbook II. The Combat Focus feat itself granted a Will save bonus once you focus yourself at the start of a fight (by hitting an opponent or something IIRC), which doubled once you had something like 4+ Combat Focus feats in total. The other CF feats granted other benefits while focused, which also improved once you had 4 or more of those feats in total. Check the PHB 2 to see if those feats would be a good fit for Clan Zaitsev, Vutall.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.