During one of the recent Devstreams, DESteve mentioned that the Perrin Sequence was the most unpopular Syndicate up to that point (I think it was a week or so after the Syndicates were released). He kind of mentioned on the sly that they "might just have to do something about that" (to paraphrase). With Mag's new mod Shield Transference, DE (and The Perrin Sequence) have delivered. In spades.
For those of you unaqcuainted with Mag, she happens to have one of the most powerful abilities in the game: Shield Polarize. The only thing it's useful for against Grineer and Infested is restoring teammates' (and excavator/defense pod) shields...but use it against the Corpus, or the Corrupted Corpus in the Void, and oooooh boy! It is destruction on a magnificent scale.
Besides Trinity's Energy Vampire, it's the only directly-scaling damage in the game (that I can think of off-hand). In other words, it takes a direct percentage of enemy stats and bases its damage off of that--in the case of a maxed Shield Polarize, Mag can drain 100% of the enemy's shields and return that 710% of that amount as damage, whether the enemies be level 1 or 1000.I favor range over damage, and with Overextended, Stretch and Mag's Arcane Coil Helmet, I can hit everything within about a 65m radius. That equates to an area of 13,273m^2...which can hold quite a few enemies. Granted, Overextended drops the power a bit...but because this ability isn't affected by duration, I'm free to use Transient Fortitude and Fleeting Expertise, which allows me to use Blind Rage...ultimately meaning that I can drop 100% of enemy shields over that huge area for a discounted energy cost, and look pretty while doing it.
But enough of my bragging; let's talk about this new mod: essentially, what it does is give Mag everything that Rhino users have been begging for in Iron Skin: a scaling ability that works as well at level 100 as it does at level 10. Details are scarce right now, but from what I've seen it takes up to 50% of all of the shields drained from enemies and adds them to this bubble. There's no indication as to the health of this bubble that I've seen, so it's impossible to tell how it works...does it refresh every time Shield Polarize is used, or does it keep accumulating shields? I believe it is the latter, as I've cast Shield Polarize with nothing around, and the shell remained strong for the next fight. Also, I'm not sure if it's affected by Power Strength mods, but it really doesn't need to be.
That means that I can tank Corrupted Heavy Gunners like nobody's business. Consider this: how long does it usually take for shielded enemies to take each other down using Nyx's Chaos? In my experience, it takes quite awhile...maybe 20 seconds or so (if they aren't hiding from one another). Using this ability, you've just taken half of the durability of all of those enemies around and added it to your own.
A level 101 Corrupted Crewman has 11,400 shield health and Corrupted MOAs have 19,000, going by the excellent Enemy Level Scaling page done by MarioVX. Let's assume about 25% of the enemies in a T4 Defense mission are composed of each of these in equal amounts, and we're facing a wave of about 80 enemies...if nobody takes down any of the shields before they're polarized, Mag can add 57,000 (from crewmen) + 95,000 (from MOAs) to her shields! And that will carry into the next round, where more will be added, and more and more and more...
Essentially, it gets to the point where the amount of shield has no bearing whatsoever, because for all intents and purposes it's permanent for the mission; so long as you keep casting Shield Polarize (and who wouldn't, given its scaling damage), you don't have to worry about it ever going away. Which brings us to our next section...Weaknesses.
From what I've seen, this shield is bypassed entirely by electrical damage (Vor's lightning, Provas and Lankas), and magnetic damage (such as that from Corrupted Lancer's grenades and Railgun MOAs, I think). I haven't tried to use it against Napalms, but I doubt it will stop any of the stronger Grineer attacks, either (blasts, fire, etc). I don't know if it will stop Drahk Masters from stealing your weapon. Curiously, the shield disappears and is disabled if you go invisible--my stupid Huras Kubrow got me killed a number of times while I was soloing Elara (I don't know if this is a bug or intended). Also, it doesn't stop knockdown effects at all, and in fact your warframe's main shields will still be damaged by things such as Corpus door barriers. Also, the shield is small enough so that parts of Mag will stick out from time to time--like her arm when casting Shield Polarize. I don't know if she's vulnerable at that time, but it certainly seems like this shield quickly starts to lose its effectiveness once you've gotten the full complement of Corpus and/or Void enemies. It seemed to me as if I was taking a lot of damage from sources I couldn't quite pinpoint...but mind you, this is like after 40 minutes of soloing Elara, or around wave 40 of a T4 Defense mission.
So what's the end verdict? This new mod is simply awesome. It is one of the first Syndicate mods that I actually feel is worth giving up a slot for. It basically makes Mag a tank, changing the entire paradigm of her game. I can imagine that in the late-late stages of a T4 endless mission, she will far outshine Rhino as a tank, and in some ways Valkyr as well (only because she doesn't have to refresh it). As far as I'm concerned, this is all fine and good--Mag has long suffered from the relative weakness of shields compared to armor (who cares if you can restore 100% shields if they drop in two shots anyway?), and this mod allows her to truly shine as a master of them.
So now, the inevitable cries of "OP!" are going to come in, and I understand completely. But when I noted that the Synoid Gammacor does 531%* more damage than the Rakta Ballistica in the official forums, few of those who had access to the Gammacor cared, and on they went selling their guns for 300 plat while laughing at offers to trade. Now that The Perrin Sequence has a mod that single-handedly creates the most powerful Warframe in the game for any mission involving Corpus, why should I care?
To be quite honest, I don't. Not one bit. Because from what I've seen, DE is going to nerf it if it needs to be nerfed (along with Trinity), or the next round of mods will make up for it somehow and life will go on. But let me tell you--life is pretty frickin' good for a Perrin Sequence Mag right now :)
*531% more damage is based on the maxed mod generic build using the weapon comparator at Warframe-builder.com