Naraku

Now just so everyone know, I've only watched the shows. I've seen every movie and every episode of Inuyasha. But I haven't read the manga so do not be upset with me if some of my thoughts are different.

I believe that Sesshomaru, at any point in time could have killed Inuyasha. Yes, their father did leave Tenseiga to Sesshomaru and Tetsusaiga to Inuyasha, making it futile for them to fight. But look at everything that happened.

In the early episodes, Sesshomaru used a human arm from Naraku and showed Inuyasha the Wind Scar. He could've easily just used the Wind Scar on Inuyasha.

The episode where...

His glare was piercing the volpe demon. "What is it?" he asked, irritated. "Um..Well, It seems Ayata..is missing..?" Shippo said, his voice getting smaller and smaller. InuYasha stood up. "what? Why didn't te tell me this before?!" he asked,almost yelling. "well..Um..She told me not to tell you..That she left.." Shippo whispered, flinching back. InuYasha sighed. That afternoon, Ayata and InuYasha got into a fight.. She left, and hasn't returned. InuYasha ran after her scent, which led into the forest. Damn shippo..He should've told me ealier, and not make me worry about that damn Ayata!
InuYasha...