Shyv? Really? She was one of the first sleeper OP toons out there, nobody played her until they saw her in tournaments w/ CC heavy teams, and she dominated, not to mention her counter jungle is godly.
Viktor doesnt need a rework, what he needs is an updated passive, Riot essentially gimped Viktor using that slot for his passive, and especially bc it only allows 1 upgrade, and the only one worth it is the Death for the stats. Viktor was meant to be able to fulfill multiple roles as a caster, Support, Nuke, AP Tank, but his upgrades are lackluster, and only allow him to shine as a APC, so I can see why they are doing that with him, his late game is one of the worst for APC.
The rest of the list looks good, Sejuani, Poppy, Heim, Karma are all toons that could use updates and reworks. In the right hands, they do well and have their strong points, but its hard to fit them into a team w/o building one around them.