"Rikimon" doesn't digivolve to or from anything.It is rather foolish and is the one that destroyed Warriorhowlmon in the first place.A mega,Rikimon wanted to take over the Digital World,but Warriorhowlmon's sacrifice stopped him.
Back Fire:Reverses fire attacks back to the source
Fire Blast:Breathes a blast of fire that cannot be dodged but can be blocked/parried
Magma Burst:Lava comes from in between it's scales and follows the target without stopping
Lava Claw:Attacks with claws after gathering energy to create a powerful fire