WS:7 BS:10 S:10 T:4 W:6 A:4 LD:10 2+3++
A spartan is the halo universes form of a space marine; they are genetically modified human soldiers. The key word in that is human, because beyond a few modifications that all a spartan is.
So at best, his overall statline might be comparable to that of a space marine. Obviously for chief two or three wounds and a leadership at ten would be about right.
As Wusword77 pointed out, that armour and invulnerable save is way over the top. A +4 save seems reasonable, +3 might be possible, but +2? Come on, spartans can't take direct hits from tank rounds like marine terminators can.
And in regards to the invulnerable save, remember that the shield used by spartans is not terribly advanced. ++5 or even a ++4 would make sense but nothing beyond that.
Special Rules: Fearless Relentless Deep Strike Feel no Pain Preferred enemy: Tau, Tyranid Eternal Warrior
Why the preferred enemy against Tyranids and Tau? Has he had loads of experience fighting them? (Note that just because he has had experience fighting the flood and the covenant does not give him tons of experience vs. either of those two.)
And then what about feel no pain? He certainly feels it, and it can stop him rather easily to boot. How many times in game have you had to find a health pack, or hide in some corner while your shield recharged?
Finish the Fight- When the Master Chief dies put the large blast marker on him all units under this marker die and the Master Chief goes back into reserve.
Last time I played a halo game, death didn't cause a decent sized explosion that killed anything near my corpse. What suddenly is letting this happen? And you do realize that for the most part, when you respawn, everything that occured from that point to when you died is reset right? Death is death in this case.
Perfect Aim-The master chief is such a good shot that he can snipe someone several miles away with hip firing. There fore he re-rolls to hit and wound when shooting.
But chief doesn't have perfect aim, no better than any augmented commando anyway. Hell, even space marines of the 40k universe aren't perfect shots. Also note, your giving him a reroll to hit is redundant with that unreasonable BS10
Sheer Audacity- If the master Chief Deep Strikes,and he rolls a scatter all units that he passed over are tank shocked (if the unit fail there leadership test each model passed over takes a str5 hit) and the master chief takes a wound with no saves aloud.
Why? And where did that strength 5 bit come from? This makes no sense, please clarify why there is some meteor like rule?
Enormous strength-The Master Chief is so strong he counts as a monstrous creature in CC.
But there has never been anything to back this up so what the hell?
Luck of a thousand men: The master Cheif is so lucky he can roll a die when he drops to zero wounds if he rolls a 4+ he comes back up with one wound.
What? So not only did you give him feel no pain, which makes very little if any sense, and nearly the best armour and invulnerable save and another special rule that brings him back, but now you give him another rule that can bring him back from zero wounds without having to be brought back from the table edge? Come on now.
Wargear: Assault Rifle Assualt 6 str 4 ap4 rending 36"
What? This is a standard issue rifle for regular troopers in the halo universe and its only moderately effective vs normal men in armour. As Wusword said, S3 with ap5 or 6 would be right for this thing, as well as assault 2.
Pistol str 5 ap1 48"
What? How many enemies can you readily one shot with the halo pistol from the other side of the map?
Just to point out, MC would eventually run out of his own ammo and have to use something else.