Like, tell me all that you know. Well, especially if you know how much HP he has XD.

best strategy that i personally know.

Use a stun seed on him, and then get close(or far, depending on your moveset) and attack, then use a sleep seed and figh until he wakes up or until you have low hp. If you have low hp, dont wanna use reviver seeds(or dont have any left) and no healing items, stun seed him again and walk away holding A and B so that your hp is refreshed.

thats how I won, only used about 2 reivver seeds.

LOL, now if only I had anyhing left. I guess I am winging it. I have to keep training, cuz I lost to him, like, 3 times already.

i was the same as you, i was having trouble. So t\what I did was that I headed back to treasure town and resupplied, evoiding as many battles as I could up to dialga.

I don't think I can. But, I haven't tried. I mean, i am already up to the summit, so idk.

just when you get up to the base of temporal tower, head back and you will be at lapras. If you have already started climbing the temporal tower then you have to be very lucky. Try raising your level.

Yea, thats what I plan to do. I'll tell you about my game:
I am a level 39 pikachu (REALLY close to 40)
Moves are:
Wide slash (Love it)
Discharge (Love it too)
Shock Wave (Awesome move)
thundershock (Nice move)
With My partner Level 39 Turtwig
Moves are:
Bite
Crunch
Razor Leaf
Giga Drain
Oh, and do you know anything about Diagla, like HP opr Level?

are your moves linked? and yeah, you might wanna level up a bit, since I was having trouble but beat him at level 42 i think.

Have your partner only have gigadrain set, so it heals if it gets attacked. So, here is a good strategy:

Start off by stunning dialga, then get far enough to see him on the edge of the screen. Use shockwave on him a few times, hopefully paralysing you. If he uses roar of time, use the turn that he is paused as an oppritunity to get a bit farther away from him.

It was kind of easier for me when I froze him with ice fang and then my partner unfroze him doing massive damage fire move. So really, you are gonna have to fail at the fight and then head back to trasure town to restock on things and level up.

Eh, with my stratgy, we will beat him in a few fights. My stratagy so far has been:
Hit Diagla with discharge, If I get lucky, he may get paralyzed, thats just a bonus and makes it a bit easier. But either way, I hit himn with Shock Wave next. If I have seeds I throw them, if not I start attacking with Mymost affective move on Diagla; Wide slash(I don't know why, but it is). But, the Giga Drain idea is a good one.

Reviver seeds, Level 50 team, good moves, and sleep seeds.
That did it for me.

same here

quote low_snow

Reviver seeds, Level 50 team, good moves, and sleep seeds.
That did it for me.

well, glad you finally got through the last main storyline boss, Hazel. Good job!

Great job... oh man for me it took me forever but all the stuff u guys say like get 5 or 6 sleep seeds and have a high level team.... I didn't need that stuff I was level 42 and my partner was level 43, with no seeds and no berries along with no hacks I beat him! The only attack you need to do that is smokescreen that way most of his attacks will miss u

oh nice