Rathian is tougher than Rathalos.
Rathalos is a large, two-legged wyvern with a spiked, armored hide covering its body. Rathalos’ outer carapace is much lighter and more vibrant in color than its female counterpart the Rathian, being primarily bright red with black markings throughout.
Silver Rathalos has the strongest flames and greatest flight mobility of any known Rathalos species. Its abilities and strength are considered equal to that of an Elder Dragon.
The Rathian is a difficult fight that will take a long time. When preparing food, eat a meal with plenty of health and defense abilities. The Rathian likes to charge back and forth, which can make it very difficult to survive against them if they hit you multiple times.
During the breeding season, the spines on Rathalos’ head grow larger and he uses them to build a nest before mating with multiple Rathians. After mating with them, Rathalos observes the “Rathian Battle Royale” and accepts the victor of the battle as his true mate.
Rathian is the female version of the Rathalos. It shares many characteristics with its male counterpart, although Rathian tends to patrol its territory on the ground. Its tail tips are full of venom.
Don’t underestimate it – pound for pound Rajang is widely considered Monster Hunter’s most powerful monster – and that includes Elder Dragons. Rajang is the only non-elder monster that preys on Elder Dragons. It seeks out Kirin and eats its horn to boost its lightning abilities.
Known Deviants that can be considered Ancient Dragon level monsters include Hellblade Glavenus, Dreadking Rathalos, Dreadqueen Rathian, Silverwind Nargacuga, Grimclaw Tigrex, Crystalbeard Uragaan, Thunderlord Zinogre, Deadeye Yian Garuga, Elderfrost Gammoth, Boltreaver Astalos, Soulseer Mizutsune, and Bloodbath…
Even Velkhana, an Elder Dragon that performs deadly ice attacks; Rajang’s weakness is easily eclipsed by the sheer strength Rajang possesses.
Speak to the housekeeper in front of your house in Seliana after completing the assigned quest “Absolute Power”. Complete the quest “Blizzard Blitz” and discover a master rank Rathalos b>.
The best elemental type to use against Rathian are Dragon Weapons, which are particularly effective in their head and wing areas, so aim for those whenever possible. If you don’t have Dragon Weapon, Thunder is the next best element against them. Again, their head and wing areas are the most vulnerable.
Rathian can always be found at the location where she was first fought on Mt. Harzgai, but there is no fast travel to get there. Another method players should utilize is by searching Monster Dens in Alcala. Rathian will appear in the monster lairs after the first encounter, but it’s a rare chance.