The tier lists on this page are subjective in nature, and are the products of their individual authors. You can only trust a tier list as much as you trust its author. Tier lists reflect the understanding on relative character strength at the time that they are written. Metas can develop and characters can change after a tier list is made. Tier lists usually do not account for character difficulty, but that can sometimes be a factor depending on the author. Depending on your goals and how competitive you are, tier lists may or may not be entirely irrelevant.
Klaige's Tier List
Kalige is a long term competitor in multiple Guilty Gear games at a very high level. They are known for their 
Anji as well as speed running.
Source: Youtube
Quash's Tier List
Quash is a top level +R player from California, USA who also played in Japanese arcades. They are now a mentor for 
Johnny and helps new players.
Source: he told me so
Teresa's Tier List
Teresa is a long term competitor in multiple Guilty Gear games at a very high level. They are known for their 
Jam. Their opinions are sometimes considered controversial and unusual.
Source: Twitter
Tarkus' Tier List
Tarkus is a Guilty Gear guide maker and data miner. He is responsible for writing or researching large amounts of the Dustloop wiki. They play 
Venom with a secondary 
Testament.
Source: Dustloop User Page
Unordered within tiers
DQRF's Tier List
DQRF was a long time community mentor from USA: California with a decent track record in competitive +R. They play 
Sol and Akatsuki's Blitzkampf.
Legacy Tier Lists
Japanese Wiki Tier List
This is a transcription of the tier list found on the Japanese wiki for Guilty Gear.
Source: seesaawiki
Kisha Tier List
Kisha was a top 
Faust player from Japan back in the pre-XRD era of Guilty Gear.
Source: Twitter
Unordered Within tiers
Ruu Tier List
Ruu was a top 
Bridget player from Japan before migrating to Strive. Some liberty has been taken with the translation of the tier groups to make them fit in the template.
Source: Twitter
Tier List Adjacent Data
Japanese Arcades used to keep track of the winrates of each character tracked via Player Cards and automatically generate "leaderboards" demonstrating the performance of each character. This is very clearly not a tier list and is heavily biased by the performance of a few arcade bosses. The data is being recorded here simply for historical record keeping because the original Japanese website was taken offline in 2016.
- Justice: 133.2
- Potemkin: 131.5
- Testament: 131.2
- Kliff: 127.6
- Eddie: 125.8
- Slayer: 125.1
- I-No: 124.2
- May: 123.5
- Zappa: 123.3
- Dizzy: 123.1
- Axl: 122.3
- Faust: 121.9
- A.B.A: 121.4
- Sol: 117.2
- Millia: 115.7
- Anji: 115.5
- Venom: 114.9
- Johnny: 114.8
- Order Sol: 114.2
- Baiken: 114.2
- Ky: 113.4
- Robo-Ky: 113.4
- Jam: 111.9
- Chipp: 111.5
- Bridget: 109.6