Well, now I know what your talking about! Kurt Zisa, why didn't you say it the first time! Well, I can't help you there.
lol, but seriously, I think I just hack n' slashed away at it. You know, like any normal baddy with no weird things to do to kill it. Can't completely remember though. (He's the easiest of the three that you mentioned btw)
Now, on the Ice Titan, [I think] the way to hurt it is to deflect the ice shards back at it. With either the ability Guard or just attacking it. (Someone please correct me if I'm wrong). But I am for sure that you need to somehow deflect the shards back at him.
-Sig credit goes to PhilXZ. The pic of Kairi's head was cropped by Rathalos9. Apparently no one else can crop Kairi's head...