Alatreon Advice

So this guy is pretty tough... Did anything change for it besides getting new moves? What weapon and armor set should I bring along for say longsword or gunlance? What items should I bring? Help.

For Longsword, I don't know. But for what to eat, make sure you get the Drink + Vegetables. (I think) It gives, assuming you've maxed them out, and their fresh, Health +50, Stamina +50, Dragon Res. "L". As well as if you steam it I think, you'll get Firestarter, Thundercaller, and Icebreaker. So if you have Neg. Res. on any of those, they'll all go up to +3 as opposed to to whatever they were at. And if their positive already, then it'll just go up 3. It worked great with my Hallow Jhen armor. Which had very bad fire Res. as well as Thunder and Dragon. It had good Ice Res. however.

Ala tends to be in flight mode a lot more than in Tri which isn't such a bad thing since it means drag > Ice weapons.
Some changes, there is a ballista binder near where you would exit from base that recharges every 3 min and you can use it when alas flying for a ton of free hits.
He gets a few lightning attacks in flight mode. They are as follows
Summon lightning (midair) he summons three lightning bolts in a 180degree radius surrounding him.
Summon target lightning (midair) he summons three bolts of lightning that strike one at a time and its aimed for a specific person. He taunts afterwards.
Lightning discharge (flight land) think of brachydios when he slams his horn in the ground and then explosions pop up everywhere. Same idea just with lightning. He taunts afterwards.
Lightning summon (flight land) he summons lightning directly in front of him and it moves in a straight line.
Horn thrust (land) he simply thrusts his horn at you twice
Spin (land) ala simply runs in place in a circular motion

Those are his new attacks per SE. He also gained a ton of taunts that he does after certain moves.
Backhop fireball (land)
Triple smash (flight)
Lightning discharge (flight land)
Lightning summon (flight)

That may not sound like much but considering all his other attacks and how he's vulnerable during them it makes the fight much faster. Also important changes.

Webbing is a quest reward.
Sky piercer/hurler is back to 15% break reward if you break both horns.