Sha Wujing and Zhu Bajie continue what seems to be a recurring trend: the release of evo fodder with just interesting enough active skills to make them marginally relevant. In this case only Sha Wujing is a material, but they both have decent combo-oriented active skills. As for their leader skills, they have what also seems to be trend: leader skills that rely on specific monsters being in the party. While this type of leader skill isn’t outright horrible, I think they’re more GungHo trying to be cute than anything else.
Sha Wujing as a LKali Sub
Let’s cut right to the chase: Sha Wujing is a fine LKali sub. Not only does his board change make the precise elements needed to activate, but he also covers the two elements LKali doesn’t. He also has decent awakenings, providing a skill boost and TPA. So, what’s the downside? Well, aside from have the poor stats one can usually expect from a descended drop without an ultimate, his active requires 15 skill ups to reach a fairly slow 12 turns. To make matters worse, he’s the sub boss of his dungeon making it even more costly to skill him up (I’m assuming he isn’t a 100% drop, correct me if I’m wrong). The stamina required to skill him up makes him an unrealistic sub for just about everyone; people that can afford it usually have better alternatives.
Zhu Bajie as a Sub
Zhu Bajie’s applications aren’t as readily apparent as Sha Wujing. Skill bind resists are still quite rare among farmable creatures, making her (?) somewhat valuable in that capacity alone. She supplies a good amount of HP which isn’t all that rare, but is a nice addition. Her active is an orb shuffle which will never match a Kali board change, but it has its uses, specifically in combating the new orb lock mechanic.
In the end, she suffers from the same problem as Sha Wujing: her active requires 15 skills ups to reach its full potential. While it isn’t nearly as slow as Sha Wujing’s — it isn’t nearly as powerful either, though — the stamina necessary to take it from its base 21 to something usable is quite the investment. It’d be one thing if you could skill her up with Hobgolins a la King Mastering, but the stamina investment makes her hardly worth the time. While King Masterings aren’t cheap, they’re more accessible and easier to skill up so if you need that effect, I’d just wait for the next Poring Tower.
Both as Leaders
This is pretty much the same story as with Aamir: their leader skills don’t have the necessary power level to overcome the requirement of having two specific subs. While Xuanzang and Sun Wukong are much stronger than Carbuncles, they suffer from the lack of team synergy all the same.
I do remember seeing something about a dual Zhu Bajie team clearing the Kaliseum, but I can’t find a link to it anymore (I now have a link thanks to the comments: https://i.imgur.com/erx8sas.jpg). It had over 100K HP and used Zera to deal with the Kali nuke. Outside that, it pretty much functioned like a standard tank team, using Xuanzang’s active RCV boost and Sun Wukong’s hearts to heal. This is a cute novelty, but I wouldn’t recommend chasing it unless you have a few hundred spare +eggs. That being said, that’s a pretty big accomplishment for what was probably intended to be a novelty team.
Sha Wujing and Zhu Bajie are actually two of the worst descended drops released in a long time. While they are powerful at first glance, the prohibitive cooldowns prevent them from being practical. New and/or non-IAP players need access to good farmable subs the most, but ones whose actives that are much too slow are essentially useless. Have fun waking up your Karins because at this point that’s the only real value this dungeon presents.