Power corrupts humans, no doubt, but whether or not the saying applies to Artahka is up in the air. He remained benevolent for 100,000 years, despite having absolute authority over his Matoran, and never showed signs of wanting to expand his empire or attain more authority. I don't think Artahka would want to lead. Miserix, yes, probably. Makuta are ambitious by nature, and Miserix is no exception. Helryx for sure would contend for the right to rule. Tren Krom (were he still alive)I'm not sure. He wanted to be free, but at the same time never harboured any ill-will against the Great Beings. He can see the bigger picture, and I'm not sure how much he craves power. The shadowed one is in the thick of things, as are the Barraki; both desire power and authority. There'd be many individuals who would want to lead, but Artahka would probably not be a contender.