The Official Monster Hunter 3 Ultimate Topic

Any tips on repelling Ceadeus? I got a Lagia Sword, but have enough to make a Lagia Horn. Should I use the horn or use my DBs, they're ice element but has the same attack as the sword.

If I remember correctly, Ceadeus is weak to Lightning, so you're better off using Lagia stuff if you can.

You should attack the Beard when he's in the first two areas. When it breaks he'll rush into the last area. If you don't do enough damage before he reaches the last area you will fail, so the best idea is to break the beard asap. In the last area there's two Ballista you can use with ammo you can gather from near each one. Use them to your advantage, and try to use the Dragonator in the area to break his horn.

Once everything is used up just attack. If you do enough damage he'll run away. I believe in the story based quest you can't let time run out, but in any future runs if time runs out and you do the quest again he'll start near the HP you left him at when he ran away the last time. The story Ceadeus is separate from the regular ones you'll do in the future though.