Concept sketches for Meital Klein's partner Digimon in a currently-ongoing RP.
Isomon, the rookie form, is a bio-mechanical, amphibious Crustacean Digimon. It attacks by rolling around into a ball and generating energy, slamming into its opponents and discharging this energy (Morph Ball). Occasionally, it may charge large amounts of energy into a delayed release capsule which will proceed to explode, releasing destruction over a large area (Power Bomb).
Amphimon, Isomon's Adult/Champion form, is better geared for combat, with attack patterns resembling those of the ancient guardian Torizo of Super Metroid - it is fairly fast (and may roll around into battle as well as walk) and attacks by charging its claws with energy and releasing an energy wave by slashing the air (Guardian Slash). Using the same energy, Amphimon can stop projectiles directed at it, catch them and then cast them back at their origin (Inertial Canceller). This only works for projectiles that have a physical presence and are larger than a certain mass - don't expect it to stop bullets or energy weapons, but missiles? yes.
Bathynomon, the Perfect/Ultimate form, sacrifices Amphimon's agility for added endurance, making it an effective tank. While it can also direct charged energy to its claws and uses them in battle at times (Omega Claw), Bathynomon prefers to utilize the cannons mounted on its head and arms to fire wavering plasma pulses. (Plasma Wave)
Finally, Malacostramon, the Ultimate/Mega form is a full on amphibious tank - complete with a cockpit-type structure that can be used to 'pilot' it. Malacostramon's primary weapon - and its deadliest - releases a massive barrage of homing high-energy projectiles that lock on to multiple targets and launch, leaving behind trails of glowing light (Crystal Flash). The power of the attack and its area of devastation is massive indeed - but it is balanced by its requirement of a fairly lengthy charge-up time. For moments where such will not do, Malacostramon fires bursts of energy from its mouth, or lunges with its head and claws at closer range targets.