"Brutalizing" really depends on what creatures your opponent is using, beyond just the element. cometbah gave a very nice breakdown of all affected creatures on the previous page; I'll list each element as a whole here, just for clarity's sake:
- Unupped Pegasus -1, Morning Glory -4 when flown, Crusader may lose attack after Endow, Blessing unaffected
- Black Dragon -5, Obsidian Dragon -6, Bloodsucker -2, Vampire -1, Gargoyle -2 (unless Stoneformed), upped Gargoyle -4 (unless Stoneformed), Vampire Dagger -2 when flown, Eclipse's effect sometimes reduced to +1|+1
- Emerald Dragon -4, Jade Dragon -3, Giant Frog -2
- Bone Dragon -5, Ivory Dragon -6, Flesh Recluse -3, Mummy -2, Elite Mummy -2, Eclipse's effect sometimes reduced to +1|+1
- Ash Eater -1, Brimstone Eater -1, Crimson Dragon -9, Ruby Dragon -13, Fire Spirit limited to 4|2, Fire Spectre limited to 5|3, Lava Golem -4 but allowed to grow, Lava Destroyer -6 but allowed to grow, Phoenix -6 until Rebirth, Minor Phoenix -3 until Rebirth
- Ice Dragon -3, Arctic Dragon -8, Toadfish -2, Steam Machine limited to 11|6, upped Steam Machine limited to 20|15
- Damselfly -1, Elite Wyrm -2, Azure Dragon -3, Sky Dragon -6, Firefly -1, Elite Firefly -2, Blue Nymph -1, Air Nymph -4, Sky Blitz unaffected
- Shrieker -5 (-1 if already burrowed), Elite Shriker -6 (-1 if already burrowed)
- Graviton Fire Eater limited to 7|5, Graviton Firemaster limited to 8|6, Acceleration and Overdrive hit a ceiling and act like poison, lobotomized Elite Charger -2, lobotomized Chimera may lose attack
- Maxwell's Demon -1, Purple Dragon -5, Amethyst Dragon -5, Fallen Elf -1, Discord -1 when flown, upped Discord -3 when flown, Purple Nymph -2, upped Purple Nymph -1, Chaos Power and mutants may be affected, own creatures cannot be Paradoxed
- Fate Egg progeny may be affected, Devonian Dragon -5, Silurian Dragon -9, first Scarab -1, first Elite Scarab -2, second Elite Scarab -1, Ghost of the Past -3, upped Ghost of the Past -5
- Spark and Ball Lightning unaffected unless buffed, Parallel/Mindgate creatures may be affected, Immortal -1, Elite Immortal -1, Phase Dragon -2, Elite Phase Dragon -4, Phase Spider -2, Phase Recluse -5, Lobotomizer -1 when flown, Electrocutor -1 when flown, Turquoise Nymph -3, Aether Nymph -4
Looking at the above, the main thing affected is dragons, with the exception of Light, Earth, and Gravity - in fact, these three elements mostly shrug this shield off.
The elements most strongly affected are Fire, Air, and Entropy.
Ablaze and Steam abilities reach a cap, Growth does not.
Most non-dragons lose only a handful of attack, a permanent effect similar to damage-reducing shields.