Level 14: Reactor

Build a turret first, then build two reactors(one advanced), a barracks(get ODST
upgrade, then destroy), a field armory(get population and adrenaline, mac blast
increase if you want, then destroy), and all the rest supply pads. Upgrade your
base before you start building all that nonsense though. Also grab all the
elephant upgrades. Point of this is to get ODSTs and one well stocked elephant
to hook onto the core. Make sure to put a Spartan in it and put save the other
two for vehicle jacking.

While you are preparing you're going to be attacked by some nasty Covenant
contingents. Protect and heal your reactor, jack vehicles, and to help protect
your reactor in the interim setup period, build and take your elephant and lock
it down near the reactor as a sort of mobile base and start making main infantry
out of it, they'll eventually become ODSTs. Once everything is ready, you can
attack, and reinforce using the ODST drop capability.

It's advisable to leave your elephant(and a few army units to protect it) in a
safe spot and clear out the areas ahead before moving it up. So, at the top of
the first hill is a Covenant base - wipe it out and put your own base there
before you send up your reactor, and so on. Then you can use that base's turrets
and some ODSTs to protect your elephant while you have your main force get the
base at the top of the next rise.

After I killed the second base I began to send my elephant and escort up the
ramp and was attacked, somehow, by a scarab. Watch out for this and be ready to
drop ODSTs to take it's attention while you get your elephant up safely and your
main force down to deal with this threat. I also used an upgraded mac blast on
it a few times too.

All in all, a good, solid level. Enjoy.