Disclaimer
Since Honglan was recently released, this review should be considered as an early review and things can change in the future for her.
Review
The newest and only caster for Beast, Honglan packs an impressive kit of mixing both debuffs and AoE damage. She is a sorely needed unit for the Beast’s current underperformance as compared to other factions, especially after Undead got Velenna.
The majority of her kit is tied up to reducing enemy mana, either via global speed reduction, direct mana reduction, or freeze (units cannot generate mana while disabled). For this reason, Honglan can be built as a budget debuffer without additional dupes to reap her benefits, allowing your team to always use M1 first before the enemy. This places her currently as one of, if not the strongest, debuffers in the game currently, and she can be very useful in any content with multiple enemies. Alternatively, she can also be built as a hypercarry AoE DPS spamming her ult, which does tremendous damage and CC even after the nerf. Similar to Talia’s ult of damaging all units and stunning them while healing the team and increasing mana, Honglan’s ult is more offense-oriented with a focus on DoT via Freeze damage and mana reduction instead. For these reasons, she can be a very flexible unit that can fit into multiple team comps, though she is slightly held back in flexibility due to her being a beast, which doesn’t have many good units at the moment.
The glaring weakness is her longer skill generation compared to other units, being one of the slowest similar to Jiho and Jacqueline. As such, it would be advisable to pair her with Vivianne and Talia to increase her mana regeneration and speed, while she debuffs the enemy team. Because of this, your frontlines need to be tankier than other comps since you would not be generating as many heals with Honglan instead of a secondary healer. Should your team hold until a hyper-carry Honglan casts her ult and M1, the stage is likely secured.
Single Bosses
We could not test her performance there as currently there's no boss mode available.
PVP
Honglan is an extremely strong pick with her S3 being a global speed reduction, allowing your team to always skill first, and skill more often in the long run. Her CCs are another icing on the cake to further reduce enemy DPS.
Pros
top tier debuffer,
actually decent upfront damage if you overlevel her and use her Ultimate,
flexible unit - can fit into many teams.
Cons
Beast faction. While you can throw her into any team and she will do well, it's hard to find a second good Beast to pair her with Honglan (if you want to run 3+2 faction bonus),
slow, like really low - takes her a long time to generate mana to use her skills,
really needs her Artifact upgraded to at least Legend+ to feel good in late-game content.
Ratings
Early-game PVE: S
Mid-game PVE: SS
PVP: SS/SSS
Love story

If you want to raise her Bond and unlock her skin, we already added her to our Love Story Guide.
Other reviews
If you want to check some other points of view check those YouTube reviews: