[Update 1]: Due to a discussion/argument with UnyieldingFTW. I want to be clear that this video focuses on PvE characters! For PvP, you're going to just upgrade your Apex 15 anyways! The pinned comment by Alistar Norris below mentions the best pvp characters options from CN meta.
[Update 2]: Bozel has 1 good reason for 6cost in PvE: Ancient Beckoning, Fenrir, where he can bring 3 AoEs (Earthquake, black hole, and decay).
This video is created by popular request.
Other than heroes with awakening skills, there are 5 heroes who truly benefit the most from having 6 skill points. These are heroes who lack good 1 cost skills (or have them in their side branch, which requires a Rune Stone).
What I consider "good" 1 cost skills are:
a) damage skills, when there are no 2-cost skills that are superior.
b) any skill that increases ATK, INT, or DMG %, so that you can 1-shot targets.
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