Active Skills
Top 3 Active Skills of Each Element
Victor – Large Hitbox

Saya – Small Hitbox

Ratio is how much dps is dealt compared to the best, non exclusive skill.
The Dps difference is due to hitbox size and the boss defense.
Seed Mine 2 is when you position the boss next to a pillar for max hits. Seed Mine 1 is the damage if the boss is in an open area.
Skills Vs Bjorn
Bjorn & Bastigor have a smaller hitbox. This test was done using a Libero so her exclusive skills are included with Siren of the Void.
One Skill at a time:

Complete Skill Builds:

(with pos) is when you send out the pal close to Bjorn for maximum Air Blade and Rockburst hits.
(no pos) is when you send out the pal far away from Bjorn.
Skills Vs Xenolord
Xenolord has a huge hitbox which means that some aoe skills will outperform super effective skills.
One Skill at a time:

Complete Skill Builds:

AB: Absolute Frost
HB: Holy Burst
LS: Lightning Streak
AiB: Air Blade
DR: Diamond Rain
Skills Vs Ryu
Ryu has a huge hitbox which means that some skills will outperform super effective skills.
Phase 1:

Phase 2:

Test was done with Orserk with Serenity and Impatient, no stab for any skill.
Skills Per Element
One pal with interesting exclusive skills was chosen to test the skill fruits of each element. The test has been done against different bosses. The tables show the ratio in damage between the skills.
Fire
Fire – Vs Victor & Shadowbeak

Holy Burst Comparison

Test done with 2 Faleris, one with Holy Burst and one with Flame Funnel.
Ignis Rage hits Victor 2-3 times, dps against smaller pals is 33-50%.
Serenity & Eternal Flame are included.
Grass
Grass – Vs Victor & Shadowbeak

Circle Vine 1 is when 2-3 vines hit, which happens against big targets like Victor. Against most pals only the middle vine hits, represented by Circle Vine 2. Seed Mine & Air Blade assumes that the player positions correctly.
Test done with Mossanda. Includes Serenity and Impatient.
Neutral
Neutral – Vs Victor & Shadowbeak

Seed Mine & Air Blade assumes that the player positions correctly. Holy Burst deals much less dps against small targets if it only hits once. Air Blade and Star Mine will also deal less damage. See the Saya vs Victor comparison above.
Test done with Selyne, includes Serenity and Impatient.
Ice
Ice – Vs Victor & Shadowbeak

Seed Mine & Air Blade assumes that the player positions correctly. Holy Burst deals much less dps against small targets if it only hits once. Air Blade and Star Mine will also deal less damage. See the Saya vs Victor comparison above.
Test done with Frostallion Noct, includes Serenity and Siren of the Void.
Ground
Ground – Vs Victor & Shadowbeak

Seed Mine & Air Blade assumes that the player positions correctly.
Test done with Anubis with Serenity & Impatient. Rockburst will deal less damage to smaller pals or pals that tend to stand far away.
Dragon
Dragon – Vs Victor & Shadowbeak

Seed Mine & Air Blade assumes that the player positions correctly. Dragon Skills are Super Effective against Victor.
The test was done with Divine Dragon Jetragon. Air Blade & Seed mine without Stab, super effective or Divine Dragon still came 3rd and 4th.
Electric
Electric – Vs Lily & Lyleen

Early test, before comparisons with Seed Mine and Air Blade started. Will revisit these when the next big update comes. Both Orserk and Grizzbolt were used to compare exclusive skills.
Dark
Dark – Vs Axel & Orserk

Early test, before comparisons with Seed Mine and Air Blade started. Test done with Frostallion Noct with Serenity.
Water
Water – Vs Marcus & Faleris

Early test, before comparisons with Seed Mine and Air Blade started. Test done with Selyne with Serenity & Impatient. Water has no exclusives.
Exclusive Skills Tests
More will be added they are tested.
Cawgnito

Test done Vs Saya, it includes Siren of the Void and Serenity.