Endeavoring To Awaken --A Guide To Rune Fencer

After the Jun 17th 2014 version update, resists on skillchain damage were removed and a damage bonus/reduction was added to skillchain damage based upon the target's elemental resistance.
Because of this, we were able to gain important information about monster's resistances which can be used both tactically and to expand the worldview.
These pages explore the interesting world that this information provides.

How to read the chart
The listings for Magic Damage Taken +- were measured using en spells and the blue mage spell Thousand Needles and Magic Defense Bonus was calculated using Swipe.
Skillchain damage decreases as the elemental resistance is higher and increases as the resistance is lower.
For example, on Fire Elementals which are weak to water and strong to fire, Liquefaction damage is reduced to 5% of it's original value while Reverberation damage is increased 150%.
The skillchain damage multiplier is seperated into the below 15 levels, no other levels exist.

High resistance | 5% | 10% | 15% | 20% | 25% | 30% | 40% | 50% | 60% | 70% | 85% | 100% | 115% | 130% | 150% | Low resistance

For skillchains with multiple elements like lvl 2 and 3 skillchains, the elemental with the lowest resistance is chosen. When there's no difference in the resistance level, the game picks it in the default order of the game's magic list Fire Ice Wind Earth Lightning Water Light Dark.
For instance, for something like mimic's which have 100% for all elements, Light skillchains will be treated as fire damage and Dark skillchains will be treated as ice damage.
Furthermore, for Lynxes which have 100% Fire 115% Wind 60% Thunder 115% Light, Light skillchains will be treated as wind damage, while treants which have 130% Ice 100% Earth 100% Water 150% Dark, Dark skillchains will be treated as dark damage.
Therefore if you want the Dark Elemental Magic Attack Bonus from the pixie hairpin +1 to apply a Dark skillchain, you need to to pick a family like treants with the aforementioned resistances or you need to adjust elemental resistances as stated below.

During the magic burst window that follows a skillchain, the elemental resistance rank goes down by 1, due to this lvl 2 and 3 skillchains in 3 part or more skillchains can have more complicated cases.
For instance, on bats which are 130% Fire 150% Wind 130% Lightning 150% Light, if you do Atonement -> Resolution, the Light skilchain damage becomes wind damage (Wind has the higher priority of the two 150% elements). However, if you do a 3 part chain of Immanence Fire -> Immanence Thunder -> Resolution, the Light skillchain damage becomes fire damage. (During the MB window of Fusion, Fire and Light resistances are removed and the resistances become 150% Fire 150% Wind 130% Lightning 150% Light and the higher priority fire is chosen instead).
Also, the elemental resistance rank reduction is reset after each skillchain and doesn't stack so you can't do longer skillchains to decrease the resistance rank further.

For elements in which the skillchain damage multipler is 50% or less, spells of that element get guaranteed resists of either 1/2, 1/4, 1/8, or 1/16 damage.
For instance, when casting water or kaustra on Coppercaps which have 40% Water 50% Dark you're guaranteed to get a resist, even if it's a Too Weak mob and you use Elemental Seal, Frazzle, Focus, Langour, etc..., you will be unable to get a full damage hit.
However, certain exceptions exist. As mentioned above, MB can reduce the resistance rank. Rayke and Subtle Sorcery can also be used to enable full damage to be reached.

Since the MB window reduces the elemental resistance of the matching element(s), a 50% element rank would change to 60% thereby eliminating the guaranteed resist and allowing a full damage hit to occur.
In more detail, in the case of the Coppercap with their 40% Water 50% Dark, if kaustra is cast during a MB window, the Dark will be 60%, removing the guaranteed resist and allowing a full damage hit can occur. However Water would still be only 50% during a MB window so you'll still get a resist.

The RUN ability Rayke reduces the elemental resistance level by 1 rank for each rune harbored by the user (The resistance lowered corresponds to the elemental of the rune, ignis will reduce fire resistance).
Up to 3 runes can be harbored at a time, so up to 3 ranks can be lowered at a time (Duration 30 sec, 47 with 5 merits and Futhark Boots, recast 5 minutes).
Therefore for resistance ranks as low as 30%, during the duration of Rayke's effect, they can be brought above 50% and eliminate the guaranteed resist.
For instance, Ahriman's with their 30% Dark, they will always resist khaustra. However, while Rayke is in effect Dark resistance will be raised to 60% allowing a full damage hit.
If it's within a MB window, it would allow even Yztargs with their 25% Stone to take full damage.

The BLM 1H ability, Subtle Sorcery, does not reduce the enemy elemental resistance rank but increases the PC's magic accuracy in a special way that allows almost guaranteed full damage on elemental resistance ranks as low as 20%.
The coppercap mentioned above becomes no problem, and even toads with their 20% Water will nearly always receive full damage.
However once you reach the 10% level it suddenly becomes very difficult, if you tried to use it on Seiryu with it's 10% Wind, you'd be lucky to even get one full damage hit spamming Aero throughout the duration of the ability.