Good story so far.

Good idea to put the Fourth Doctor in. If I'd improved the Five Doctors, I would have put him in... mainly for comedy since he's funny, even having the nerve to joke around with villains like Davros. And since you put in the jelly-baby, I suspect he plans to steal them.

Martha and Mickey in? I bet they'd do well. They're not easy to scare.

Here are characters you can put in:

Sarah Jane Smith and her gang.

Maria Jackson and Alan Jackson (Maria's dad)

Rose Tyler

Ace

Brigadier Lethbridge-Stewart

Emily Morris, the girl who helped Sarah Jane in Lost In Time.

Some Daleks including a Supreme, a Strategist, two or three Scientists, and a dozen Drones.

Some Cybermen including a Cyber-Leader and a Cyber-Lieutenant.

Some Sontarans led by a major, a captain and a lieutenant or a sergeant and a corporal. You can even give them names.

Some Rutans.

Some Silurians... split into two factions. One would want to help the humanoids, while the other want to exterminate them.

Four or three Slitheen. They could even join forces with the Master.

A herd of woolly mammoths. They can even befriend the goodies after Rose saves the matriarch's grandson and even help them.

A few dodos. They too can help the goodies.

A woolly rhino

A Brachiosaur. He or she can also help the goodies.

A Triceratops

A Stegosaur

A Styracosaur

A few Iguanodons

Four Pteranodons

A herd of Diplodoci

A sabre-toothed tiger

A Tyrannosaurus rex

A Spinosaur

A pack of raptors (Velociraptors, Utahraptors, Dromeosaurs, Megaraptors or Deinonychuses)

Some Nazis including a captain and a lieutenant

A squad Judoon including a Judoon-Captain. They can be hunting the Slitheen.

A Blathareen or Rackateen who was sent by the Grand Council of Raxacoricofallapatorius to help the Doctors and their allies for how a future Doctor saved them.

A few Ogrons.. recruited to aid the Blathareen or Rackateen.

Nakie 8th? Please let that be a naked 8th doctor, don't really fancy seeing one of the other 3 options naked or thinking of them that way, or inflicting it on any other poor person.

OMG SO FREAKING FUNNY! u should so write more about this!

Does this mean that we'll get to see Romana? She was trapped in the Time Scoop with the Fourth Doctor, after all. I can just imagine her reaction to the Thirteenth Doctor - "I see you haven't gotten any better at regenerating. In fact, I'd say you've gotten worse."

And the Ninth Doctor's claims of being nine hundred, - "Doctor, not even you could go through four incarnations in less than three hundred years." (He was around 650 when she travelled with him).