Those who pay close attention to the blog may notice that at one point, I was "rather dismissive" of Hybrid Swordmages. Hybrid Swordmages, as far as swordmages go, are nearly universally better than their non-hybrid breathern. Swordbond is by and large a relatively useless feature, Swordmage's Warding can be regained through Hybrid Talent, and unless you hybrid into a class without leather armor proficiency, you're not losing anything on AC (and even if you are, it's another feat). In short, except for being marginally feat starved, hybrid swordmages have one-and only one-downside:
Their defender feature is usable only "once per encounter." That sounds like madness! And if that were really the case, it would be. But rather, Aegis of <Whatever> Is usable once per encounter to mark, but usable at will to trigger, and can even mark multiple enemies at once.
An ordinary swordmage gains very little by repeating his usage of Aegis to mark enemies, because he unmarks previously marked enemies. Since Aegis lasts until the end of the encounter, this means that in a lot of cases, unless the "Face of the battlefield fundamentally changes," there's not a lot of difference in the mark feature of a hybrid swordmage compared to a non-hybrid.
The bottom line is that, it doesn't take anything to "Remain a defender" as a hybrid swordmage. This means that, unlike the Fighter, you can actively pursue your other class (usually a striker) while simultaneously being roughly as potent of a defender as a full class swordmage.
Prior to my Solo Monster rules, Hybrid Swordmages were particuarly effective against solo monsters-after all, they literally marked the entire encounter from the outset. With the universal ability of solo monsters to negate marks though, hybrid swordmages are hit with the harshest rules scenario since third edition-not quite akin to a wizard facing an Iron Golem, but running a bit close.
So what's the solution? Again, it's not just important to realize what the problem is, but to realize why it's a problem. The essential solution is to look fundamentally at how hybrids are "supposed" to function (assuming that they're even supposed to-I'll look at hybrids more generally later, but for now, let's just look at the concept). Striker features only apply to the class powers of said striker class. If you look at the Defender, instead of triggering whenever the defender attacks, it triggers when using Fighter attacks.
Seeing a pattern? The basic premise is that, in order for the Hybrid Swordmage to make sense, instead of arbitrarily limiting how often the Swordmage can mark in terms of encounter resources, we need to make the Swordmage play like a swordmage.
My fix is simple: Aegis is an at-will power. The immediate action related to Aegis is not. You can only use Aegis of Assault's Immediate Reaction, for instance, once per encounter. The trick, however, is that whenever you hit or miss using a Swordmage attack power, you regain the usage of your Aegis power. What's really nice about this build is that it stops hybrid Swordmage/Avenger (or I guess hybrid Swordmage/Paladin) that uses Power of Skill from being the only reasonable option for an Assault Swordmage-after all, now those Swordmage Encounter Attack powers that can be used in conjunction with Aegis of Assault actually recharge Aegis of Assault.
If enemies are triggering your aegis every round, you're going to have to be using Swordmage powers every round. This prevents "Archery Shielders" so to speak from standing back from 10 squares away and using Aegis of Shielding every round; there are no super long-range Swordmage attacks, because Aegis of Shielding wasn't intended to be used at super long range as a rule of thumb.
If you happen to have Rapid Aegis Reaction, you may find you can't use Aegis of Assault for both your bonus immediate, and your standard. But on the other hand, if you're a hybrid defender and you only have one option for Immediate Actions per round, you're probably not hyper optimized in the first place