heck no
after you defeat Cyrus you can battle dialga then you battle the three lake Pokemon and move on to sunnyshore city. then you go on to defeat the elite 4.
In Pokemon Platinum, you don't battle Cyrus at Spear Pillar. Instead, you fight him in the Distortion World. After beating him, Cynthia heals your Pokemon and then you battle Giratina.
Cyrus the galactic leader
No. After you beat Cyrus for the third time, he leaves and never returns.
Battle and defeat Cyrus in veilstone building
You could win or you could lose, what does it matter?
You go to the lake and battle Cyrus.
The final battle with Cyrus is held on the highest point of Mt. Cornet. He tries to summon the legendary Pokemon to rewrite the universe. Cyrus disappears after his defeat leaving Team Galactic to Saturn.
GO to the spear pillar. go to youtube and write How to go to the Spear Pillar in Pokemon Platinum.
you will just have to try and remember the way out or battle Cyrus again and then Giratina
Cyrus will have one when you battle him in the Team Galactic headquarters in Veilstone City.
You have to enter Mt. Coronet through Route 207, and go with good pokemon, because you battle Mars and Jupiter, then Cyrus, then you battle and try to capture Palkia. (Hint: Use the Master Ball Cyrus gave you. You don't even have to hurt it.)