With the Storm of Magic now lurking dangerously above our heads, i've taken some time to kit out a Slann I can use not only to boost my army's power, but also to counter the enhanced power of casters, and whilst planning for a Wizards + Monsters SoM game (500pts each of Wizards and/or Monsters), I used what i'd learned last time to decide that Lore of Light, when a full army is thrown into play, becomes a damn good lore to take.
First off, the buffs. Only HE are likely not to benefit a lot, but for every other army, I10, extra attacks and
ASF can be a godsend, especially for Lizards, should you reach combat. Gunlines won't benefit as much, but then you'd only need Light as a secondary lore for those anyway, since Shadow would be better with the hexes.
The casting values are also not that bad either, with spells 4 and 5 needing only 10 to cast normally, and 13 to cast boosted; only Time Warp is in any way difficult, but only when boosted; outside of that it's only a 12, making it the lowest-costing 6th spell of all the Lores, and only average for every spell anyway; heck, half of the Lore of Shadow is harder to cast.
For the best results, use Light in conjunction with Shadow, namely Withering and Enfeebling. I say this because whilst you have the army buffs, you also have the wizard-killers. With Arcane Fulcrums now offering a 3+ ward save to those upon them, people will often forgo protection in favour of offensive items, and this is where Light comes in. A 3+ ward save is by no means the most difficult thing to bypass ever; i've lost enough Chaos Warriors, Chaos Space Marines and Tau Battlesuits to know that 3+ isn't the be-all and end-all of saves. I would also like to point out Banishment, a spell I haven't much looked at until the Fulcrum ward save came into existence, but now i've looked closer, there's a nice little passage that might appeal to people, "Successful ward saves taken against Banishment must be re-rolled".
All of a sudden, that 3+ ward save doesn't seem so tough when faced with
2D6 hits that force re-rolls of successful saves. When used in conjunction with The Withering, the S4 aspect doesn't seem so bad either. Skaven, one of the races that will benefit most from being a on a fulcrum, will find themselves without armour, taking
2D6 S4 hits and re-rolling successful saves. Even those pesky Elves will be hurt thanks to their T3. With the only armour of most mages being the Fulcrum ward save, you can really hamstring the army with a Banishment, perhaps even kill the wizard in one cast.
Banishment isn't all, however, the Net of Amyntok can also be quite handy. Is there a wizard in a unit somewhere or on another fulcrum that you want constantly sweating whilst you Banish his friend? Make him take a Strength test every time he want to move, shoot or cast a spell, with failure meaning he doesn't do it and takes
D6 S4 hits. Again, best against S3 armies (seeing as though it's preferable to cast on an enemy fulcrum wizard, all armies bar Chaos and Dwarves are fitting targets; there aren't many S4 wizards or casters I know of that aren't Special Characters or require the use of a magic item to make them wizards) but can be used against all just on the off-chance; I don't know of many wizards at all that are S5, so practically every wizard you cast it on will have at least a 1/3 chance of failure, if you want to make sure, you can Enfeeble them a bit.
Then we have Shem's Burning Gaze, a seemingly harmless spell at first glance, but can be used to draw out early dispel dice or to weaken/finish off foes afflicted by Banishment or Net of Amyntok; you can even up the casting to S6 to take care of those T4 wizards if you can't afford to Wither them; more often than not, you'll only be looking to cause a single wound or so, so it's worth it just to try and make things a little easier.
The only armies you might have trouble with are Warriors of Chaos (for nothing more than their superior statlines) and Daemons (for nothing more than the Standard of Sundering - But with the thought of Kairos on a fulcrum, Daemons were never going to be easy).
Whilst Shadow makes a great companion Lore because of its hexes, it's also good for its fearsome reputation and high casting values. For a casting of Shem's Gaze, Net and Banishment, 7 dice is optimal for Level 4 wizards who can generate power dice with each cast, such as a Slann with Focussed Rumination, but for other Level 4s, you'll be looking at 10 dice, since Shem's isn't necessary, and Net is only good for tackling enemy wizards who have a chance of hurting you from another fulcrum, Banishment is the only spell you'll be looking to cast regularly, and for a Level 4, 4 dice is fine to both reach the casting requirement, and beat it by enough to require more dispel dice. Since Shadow is widely known as a powerful lore, throwing a good number of dice into Enfeebling and Withering can draw out panicked amounts of dispel dice, making Banishment an easy cast and end to your Magic Phase.
Whilst Shadow is obviously a great lore, Death can be just as good; not only is it able to snipe characters and deal damage to leadership etc. but the Lore Attribute can mean that you're getting more Power Dice to throw at your Light spells; it's also probably optimal against Daemons, where you can snipe the Standard of Sundering, and let rip with Banishment against practically everything, forcing them to re-roll their ward saves and dealing significant damage.
Other lores might well also be good (Fire, for example, can help deal general damage and draw out some dispel dice, whilst allowing Light to mop up afterwards), but to me, Shadow and Death leap out as being the main counterparts to a Light wizard.
Bearing in mind I only got up about an hour and a half ago, and i've been going over this in my head for a few days now so may have forgotten things, please add your own thoughts, corrections, criticisms (constructive only; flat out criticism will be reported) and suggestions.
Thanks for reading this far, you've earned yourself... something...