Brahmin can, for the lack of a better term, give someone a Pokémon type. All eighteen types are on the table, except for Normal, and this elemental magic typically manifests within an amalgamate after a few years.
They're basically just your average elements.
Fire is your pyro magic and fiery aspects; using intense heat-based powers to incinerate opponents to ash.
Grass utilizes lethal plant life and usually involves the growth of plants. This element commands powers centered on nature manipulation, primarily using vines, leaves, spores, and solar energy to inflict damage. Energy-draining attacks are not off the table, and this element thrives in sunlight (not scorching desert heat, however).
Water is your making waves, high-pressure jets, water-bending, making a splash, all that good stuff.
Ice is frost, permafreezing, coldness, basically turning you into Elsa. Might even give you some cold resistance.
Electric is the shocking feeling that can course through the nervous system and can be generated using energy. Good luck landing a hit on them, cause these sparky little dudes are FAST.
Flying is based around the skies and clouds, wind-bending, and may also include the weather.
Fighting usually just gives you a buff in melee attacks, like biting and scratching.
Ghost is manipulating shadows, phasing through solid objects (including the ground), and just straight-up making itself invulnerable to all damage by "going ghost".
A close cousin of Dark, which does... pretty much the same thing.
Poison kinda speaks for itself; weakening the opponent over time, or just using sludge to attack. Nothing crazy on paper, but you'd be surprised.
Rock/Ground is the earth; using earthen materials like rocks and sand to attack, or just using seismic, earth-controlling attacks, enhancing digging speed.
If Brahmin makes Bug your main element, he must really hate you, because unless you're summoning a swarm of locusts or something, you're not getting far with it. Not saying it can't be strong, like some Bug-types are, but still.
Psychic is things like hypnotization, trickery, illusion, telekinetic blasts, anything that can fuck up a normal human brain.
Dragon can do the same thing Fighting does, but it can sometimes turn the amalgamate into a dragon, or dragon-like, which makes the melee attacks even stronger.
Steel hardens a part of your body (or all of it) into metal, giving it a metallic sheen. Like Fighting and Dragon, it gives you a sizable buff in physical attacks.
Fairy heavily relies on cuteness or general charm. Beams fired by those with the Fairy element appear as small butterflies.
While this is true, the magic used by the overlords is personalized, largely themed to the Deadly Sin they're meant to personify. While all six overlords utilize powerful magic, the manifestation of that magic to the lesser amalgamates is unique to each individual.