isaac0610

Best answer as chosen by Asker / Ratings
Take a flash bomb, throw at it and attack his head with any of your weapon.

kholde_stare

That's a fairly good technique there, but there are a few flaws.

You're better off if you dodge his charges as they will damage you whether or not you block. It's best if you take as little damage as possible.

Though the talons are blockable and don't do overflow damage like the charge, it requires around 100 stamina (full default bar)to block the whole thing. A better way to avoid his talons is to run under him when he flies up. You'll know whether or not he's tried to claw you and failed by the screech he makes.

On a side note, whenever he flies up and hovers like he does to talon you, it's always a good idea to be under him. His claws can't get you and the only other move he has from there are fireballs. Fireballs from the air like that have a minimum range and will not hit you if you are under him. In addition to not getting hit, being under him provides you with a few good great sword swings in as he lands leaving enough time to still get out of the way of his next move.

As for your choice of armour, I wouldn't say plesioth is the way to go. I'm not going to bother checking as I'm fairly certain about it, but I think it has very bad fire resistance. Despite what may seem like common sense, his fireball is not his only fire element damage. All of his melee has fire damage involved as well. It's been a long time, but if you read lord grahf's faq on damage mechanics you'll find a few little things like that.

In my personal opinion, just go with Kut-Ku/Ioprey or Genprey or something.

Although you can take only 5 potions if you want, more is always better. On my first Rath kill all those many years ago I had a lot of trouble. Ended up getting fully decked out with pitfalls, flash bombs, potions, mega potions anything I could get that would help. After the first few kills it gets easier and takes less preparation.

Just remember a few simple rules when fighting with a great sword.
-Unsheathe swing/roll/sheathe is your best friend for hit and run(From here on in I'll call it UnS/R/S)
-Dodging is always better than blocking(if for no other reason than to save sharpness if not health/stamina)
-Watch how fast he turns(two quick turns usually means a charge, two slow-ish turns will be a fireball. The one exception is when he does his sort of jump attack, which can't really hit you anyways unless you're against a wall, he'll do it after slow turns if I recall correctly)
-You can get roughly two swings in when he fireballs, and two in at the end of his charge if you dodged and chased him. Unsheathe/Any other swing/Roll/Sheathe and get out of the way

And as long as this is, I've got more so bear with me if you're still looking for more information.

If your first aim is to remove his tail, and it should be, there are around three good times where you can swing and get out before you can get hit. The first one is when he's landing. If he's changing zone, or just coming down from fireballs/talons you can get behind him and do a UnS/R/S on his tail right as he levels out from landing and his tail is level with the ground again. Second, after a charge, if properly dodged you can follow right behind him and UnS/R/S the tail. It takes practice to time it right, but soon enough you'll be able to fit an upswing in there before having to roll out. Lastly of course if the fireball. He leaves himself wide open when he does this. As stated above you'll know when it's coming by the speed at which he turns giving you ample time to get in position. Depending on how fast you are at getting there, you can get anywhere from one to four, maybe even more, swings in on his tail. Keep in mind though that he does wave it around and it will take a few tries to get it down.

Above all else, remember to just cut and run. It may seem like it'll take forever but before you know it he's dead and you're barely missing any health at all. The worst thing you can do is stay under him, because the base of his tail can get you with a tail whip, or he could charge. He also can leap backwards, while shooting a fireball where he just was, and due to the wind you're most likely going to get hit.

Rathian is much the same as Rathalos, though with a few added moves. There's only like three things Los can do that Ian can't. Those are any attack from the air, including clawing with his talons from the air, which inflicts poison, K.O. Doing a lot of damage, and his triple fireballs. The third is the backwards leap with a fireball. It's true that Ian will also jump backwards but she doesn't shoot fire at you. I suppose that you could also count the flying leap attack, but it's more of an annoyance than an attack so I don't count it.

Now, the Rathian is a much better ground fighter than the Rathalos, and she has more health too. Though because she stays on the ground more often she seems much easier.

So, in addition to all of the Los' moves(cept for the ones mentioned above), she brings her own unique flavour to battle.

Of these the first I'll comment on is the triple fire ball. Much like the single one she'll turn twice slowly. There's no indication if it will be one, or three you just have to stay out of the way. It will seem like a blessing for the most part, as she stands still to fire them all giving you free hits. But every once in a while you'll get careless and see just why the she does it. It's much harder to dodge them in close range as they're aimed at the ground and will explode, not just sail past you.

Now, her trademark move, which everyone knows and hates her for is the backflip. If you are caught in the wrong spot when she choses to do this you will suffer major damage as well as a lot of poison. You can see it coming, but I'm not sure how fast you'll be able to get out of the way. The only forewarning is that she takes a step or two backwards, followed by the flip and then hovering foreward a bit. If you avoid the flip part, don't get under her as she lands because she stomps as she does it. If the wind from the wings hits you first the stomp wont hurt, but if you're swinging a great sword, charging a hammer, or even wearing wind resist gear you'll get tossed back and hurt.

The final move of hers is a very annoying one, if uncommon. I don't quite know what to call it, it's a sort of fake triple charge. It's very hard to avoid, as she turns on a dime three times during what will look like a normal charge. There's not much to say about it other than keep an eye on her when she's charging. If you expect he to just fall over at the end once she's out of sight you're in for a nasty surprise if she pulls this one over on you.

For the most part just obey the rules of the great sword and cut and run and you can kill just about anything. Keep in mind this is mostly from the sole perspective of a great sword. If by chance someone actually read any or all of this my only hope is that through my knowledge of the game I've helped someone in some way.

If anyone is interested in the technique of another weapon just post your question. I've got this on my watchlist so I'll know when something gets asked.