Let’s look at some of these points.
Given that the only canon account we have of this match is in Mutran’s musings on the topic, we’ll have to go off how he phrases things.
Icarax actually had the insane courage to try to implement his ideas without approval from the rest of the Brotherhood. He left his assigned realm of Karzahni and journeyed south with a small army of Manas crabs.
The Manas were rather loyal to their home of Karzahni, so it’s doubtful they would gladly drop everything to go follow Icarax. He likely utilized Rahi Control to form his army.
Teridax then overrode Icarax’s Rahi Control with his own.
It’s not stated whether or not Icarax restrained his powers for their fight, but even powerless, a Makuta which fought back three other Makuta at once didn’t have the physical comeuppance to topple Teridax. Ignoring the second half of the fight entirely, Icarax still couldn’t physically beat Teridax despite giving him an absolute beatdown.
Once again, the only action the Manas actually took was closing in on Icarax. If there’s anything else that occurred there, it isn’t stated.
Then Teridax exerted the smallest amount of his will and turned the Manas against Icarax. Once he was surrounded, Teridax used every power at his command to defeat… no, demolish… no, perhaps humiliate would be a better word… Icarax.
Saying Teridax brought a gun to a wrestling match simply because he used the Manas is a bit of an unfair comparison. A more accurate comparison of the fight is letting a pro wrestler beat the tar out of you for six hours and when he tires out using a flamethrower on him.
Teridax let Icarax do everything he could and it simply wasn’t enough. When Icarax could do no more Teridax made sure it would never happen again. The crabs were nothing more than a means of keeping Icarax from running away.
There’s no need to be like that about it. This isn’t a ‘my dad would beat your dad’ scenario; we’re discussing a predetermined fictional fight between two robots with an audience of crabs.
Well technically he was walking for a little while after that point so I’m technically right
Icarax took the Starscream approach of rushing headfirst into the situation and avoiding additional help to prove his capability as the new leader of the brotherhood by eliminating Teridax with the simplest and most violent strategy he knew how: punch it until it dies.
Of course, it didn’t work, and when it failed, Teridax left a lasting impact on numerous Bionicle fans as well as the Brotherhood of Makuta and clearly defined why one archetype lead the Brotherhood and the other followed behind.
“If you want power, and another has it, you get it not by outwitting him — you get it by stepping over his corpse.”
—Icarax
“We both know that there are a thousand ways I could destroy you right now. And 941 of them hurt.”
—Teridax
Three, technically. Once to Vakama for various (albeit vague) reasons, once to Takanuva through means he did not anticipate (although it can be argued he intended to lose this fight) and once to Mata Nui (by being shoved into a planet).