Tandri beastrdier

Tandri felt no fear as the tendril of Hive Fleet Behemoth loomed directly over him, and the spores rained from the sky, the advancing tide of tyranids was enough to make lesser men turn and flee,but Tandri stood his ground. as the hordes of tyranids washed over him, slaughtering all that came in his way. it was then he sw something he very much liked, an enormous carnifex tearing holes through tanks, spewing acid over hordes of infantry, but what what really intrigued Tandri was the monsters ability to recover from any wound, he saw it shake off a rocket to the face, as if it were a fly, he wanted its power. for hours he wresled with the beast, both physically and psychically untill finaly. tzeentch saw this, and he was impressed, by his warriors valour, he severed the carnifex's link from the hive mind, and tandri took it for his own, now he rides into battle, on the back of his carnifex, causing chaos and bloodshed from atop his mount.

i think 350 points is fair.

WS 4
BS 3
S 10
T 7
W 4
I 3
A 5
LD 10
SV 2+ *5+
(edited so he is no longer any better than a carnifex with adrenal glands toxin sacks bonded exoskeleton) apart from an extra +1 initiative)

(all included in profile)
monstrous creature.
acid maw(reroll wounds)
adrenal glands,
bonded exoskeleton
regenerate
tail weapon sycth (d3 s 5)
sything talons
tusked (+ 2 on charge)
2 deathspitters
toxic miasma (reduce enemy ws by 1)
mark of tzeench
fearless
concentrated (tandri is a psycher, but is focusing his powers into controlling his mount, thus may not use psychic powers)

Wrestling the hive,
when within 24 inches of a synapse creature, Tandri must take a leadership test, at the beginning of his turn, if he fails, he must attempt to get into close combat and attack the closest friendly unit, this continues untill he passes a leadership test at the start of the players next turn.

I'm thinking, around 300 points unfortunately for me

For an overpowered carnifex (high WS, and very high attacks), that seems fair. Could be tricky to make it not seem like a joke though.

Plus, read the fluff on shadow of the warp, I'm no expert, but I think they can't be contacted by psychic. Each tyranid is a cell of the hive mind, and there's only one guy who ever managed to even contact it, let alone split a powerful creature from it's grasp. And anyway, that fleeting contact almost killed the greatest (actually living, not the emperor) psyker in the imperium, so fighting on it afterwards could be tricky.

For a good analogy of psychic that Kip told me, consider the warp universe to be a dark room, with the darkness representing calm in the warp, and light representing disruption. Humanity is a shit-load of candles, with huge gaps in between (big room, by the way). The whole tau race is a single standby light on a TV. Eldar are a lightbulb. Dark eldar are a slightly smaller lightbulb, but in a box, with Slaaneshi signs on the box. Necrons just don't appear.

Now, the tyranids would be a wall. Invisible obstacle. Nothing gets in or out. So it could be difficult to claim you "hacked" one, without reading more into it.

wrestled it away from the range of a synapse creature, and put an implant in its brain to stop it obeying them automatically?

You'd need to remove the mind of it, and then replace it. Would take a hell of a long time, and wouldn't be very good, since the hive mind basically is his mind. Maybe give it slow and purposeful, to show that?

one thing i hate its slow and purposefull, unless they have none assault weapons in which case its brilliant

after some offsite discussion
i have decided, he will be slow and purposefull, because the mind control device has basically made him a robot, but he will also have fleet of foot, and will charge like a beast

your having a guy ride a huge monster which is already as redickulessly overpowered as the hammerhead

basically just to give it better weapon skill and initiative XD

if this is too overpowered for anyone, i'm disallowing the nightbringer from any game i ever play ever again, as well as kugarth the plague father

Fair enough, though nightbringer got taken down by enough splinter cannons.

aye, but its damn overpowered, the only way i killed it is by rolling a 6 on turning it into a spawn.

Which is why you need lots and lots and lots of weaponry. Or failing that, Grey Knight Terminators.