When Waifu is Laifu is just not enough.
As Tier Lists may reference upcoming characters and content, they may contain spoilers.
Global-Specific Tier Lists
The Priconne Global Info Tier List - this site's own tiering system for character usability. Based on evaluations pulled from the AppMedia and GameWith JP Wiki's, the CN Tier List based on the current equipment phase., and general thoughts based on PVP/CB party compositions.
Restia's "Recommended Characters to Raise" EN Server List - breakdown of the strengths of each character and information on how to obtain them. Note that the evaluations do reference future gameplay and content updates that may not be in Priconne Global for years depending on the final schedule.
JP-Based Tier Lists
[Heavy Spoilers for Future Content] Official Priconne Wiki's Tier List - the Wiki naturally has their own Tier list of units that is relevant to the latest version of the original game. Note that evaluations are based on updates that have not yet occurred in the main game.
[Heavy Spoilers for Future Content] [Japanese Language] AppMedia.JP Character Analysis Pages - these analyses are what the Priconne Wiki's tier lists are based on. Outside of character reviews, the analyses also contain documentation about character quirks and optimization tricks.