1. Active abilities: Characters with useful active abilities based on either target mode (single/AOE), damage, or other secondary effects in the ability gain 1 point.
2. Passive abilities: Characters with useful passive abilities based on whether it aligns with the main synergy or certain characters gain 1 point.
3. Synergy and team composition: Characters that have good/useful synergies and make strong team compositions gain 2 points. 2 points because synergy is king in omniheroes.
4. Versatility: Characters that are consistently used in different game modes (PVP/PVE) gain 1 point.
5. Progression and evolution: Characters that significantly change the game when upgraded or with exclusive runes gain 1 point.
6. Community consensus: More like pro players consensus. If a character is ranked higher than average then it gets 1 point. Average or below characters gain 0 points.
This is the general rule which can be expanded to get even more specific but would require a lot of time, effort, and also over complicates it.
As mentioned in the video, don't consider this ranking as something engraved on stone. There are many reasons to it, for example, using certain characters in combination with a particular relic could potentially change the tier the character was assigned in this video.
Any disagreements and insightful opinions are always appreciated in the comments.
Make me happy and join my discord: / discord
Best tier list but a little out dated: docs.google.com/spreadsheets/...