I have a big question. it involves three books.

[drewkitty ~..~]

The short answer would be it is not totally book legal, in the strictest definition of the term.

In other words he is with in the intent of the what is written, only bending a bit of meanings of intent.

In HU2 a Ancient Master can be made as a N&S Dedicated Martial Artist.
The Immortalist class can be considered, in a liberal outlook, as a Dedicated MA.

I would let such a player use such a char.

[Tadrith]

As in a multi OCC or just taking the powers from all 3 OCC's and making one OCC with them all?

[drewkitty ~..~]

As in a multi OCC or just taking the powers from all 3 OCC's and making one OCC with them all?

There are only two OCC's talked about (Immortalist and the Dedicated MA), the latter is a canon optional AM, while the former could be, if the GM is willing, replace the DMA as the option of the AM. Nether of which would not be multi-classing with the AM power cat.

As per HU2 & N&Sr, the AM can be made as a DMA class from N&S, so there is no multi-classing involved there.(The HU2 optional AM DMA is pretty strait forward in how it is made, but the N&S AM DMA there is a bit of bad wording in the text due. This is due to some conflicting text in the main part of the book about what a (exclusive) and (primary) martial art form is.

There is also in the proposed combination of classes a fault. That is in the concept of the Immortalist class. According to the class it gets the only MAF that Has To Be The Only MAF That Char Has. So just looking at the class concept, you can not multi-class the Immortalist class.
--------------
Stepping around the stated "you can't do that" reasons..... the idea would be that you take the Wu Shih class, drop the magic stated in it but keeping skills that come with the class, and have it get instead the Celestial Calligraphy abilities. All with the AM levels and level advancement. The other change would be that the type of MA the Wu Shih was before perusing magic would be a DMA.

[Tadrith]

Not sure I would allow it myself even if you could find a good hand-wave. IMO while it may be technically possible it gos against the feel of the Immortalist class it self. Find out why the player want that class in particular, if it's because of the Chi magic then point them at one of the other magic using forms, if it's for the Immortality then I don't know what to tell you as it states that the teachers of that form feel the only way to achieve Immortality is strict adherence to any and all rules associated with that form. At that point just have him take the Immortalist OCC. Now keep in mind this is just my opinion as I have no real idea as to whats going on in your game, but that's what I would do.

[Mercdog]

A buddy of mine has mixed a martial artist OCC from Ninjas & Superspies, a Immortalist OCC from Mystic China, and The Ancient Master from hero's Unlimited. Can it be done?

With Ancient Master and Dedicated Martial Artist, I'd say it's "either-or", not both. And make the player choose between them. But if they wanted to combine the result with the Immortalist, I'd likely allow it, assuming they had some interesting background information.

Though this is just a snap judgement. I'd really have to review the material before making a final ruling.

[everloss]

A buddy of mine has mixed a martial artist OCC from Ninjas & Superspies, a Immortalist OCC from Mystic China, and The Ancient Master from hero's Unlimited. Can it be done?

I would allow an Immortal martial artist from N&SS. I would allow an Immortal Ancient Master. However, the Ancient master is allowed to have the powers of a N&SS Martial Artist if you so choose, so having an Ancient Master ALSO be a Worldly Martial Artist is redundant. You might as well let (for argument's sake) a CS Grunt take hand to hand expert twice.

[everloss]

Find out why the player want that class in particular

I think it's safe to assume the player wants to be the most munchkin munchkin in munchkin land.

[Tadrith]

Find out why the player want that class in particular

I think it's safe to assume the player wants to be the most munchkin munchkin in munchkin land.

Now that's not fair. I admit it sounds likely based on the limited info we got but he could have a particular idea for a character and that was the only way he found to make it work.

[drewkitty ~..~]

A buddy of mine has mixed a martial artist OCC from Ninjas & Superspies, a Immortalist OCC from Mystic China, and The Ancient Master from hero's Unlimited. Can it be done?

I would allow an Immortal martial artist from N&SS. I would allow an Immortal Ancient Master. However, the Ancient master is allowed to have the powers of a N&SS Martial Artist if you so choose, so having an Ancient Master ALSO be a Worldly Martial Artist is redundant. You might as well let (for argument's sake) a CS Grunt take hand to hand expert twice.

The HU2 Ancient Master has the option to be a N&S Dedicated Martial Artist class. There is no mention of being able to be any other MA class from N&S nor MC.

As a GM I would let a player choose a Worldly MA or one of the MC MA classes for their optional AM class.
The Fang Shih (geomancer), Tao Shih (Immoralist), and Wu Shih (Chi Arcanist) all are magic classes and would fall under the Magic power class.
While I might consider letting a player have his/her AM char be one of the three because they have a MAF. I would not say yes or no as a blanket opinion.

[everloss]

A buddy of mine has mixed a martial artist OCC from Ninjas & Superspies, a Immortalist OCC from Mystic China, and The Ancient Master from hero's Unlimited. Can it be done?

I would allow an Immortal martial artist from N&SS. I would allow an Immortal Ancient Master. However, the Ancient master is allowed to have the powers of a N&SS Martial Artist if you so choose, so having an Ancient Master ALSO be a Worldly Martial Artist is redundant. You might as well let (for argument's sake) a CS Grunt take hand to hand expert twice.

The HU2 Ancient Master has the option to be a N&S Dedicated Martial Artist class. There is no mention of being able to be any other MA class from N&S nor MC.

As a GM I would let a player choose a Worldly MA or one of the MC MA classes for their optional AM class.
The Fang Shih (geomancer), Tao Shih (Immoralist), and Wu Shih (Chi Arcanist) all are magic classes and would fall under the Magic power class.
While I might consider letting a player have his/her AM char be one of the three because they have a MAF. I would not say yes or no as a blanket opinion.

you are correct. A player can choose to use either the Ancient Master OR the Dedicated Martial Artist. If the GM allows it, of course.