My PC Monarchs, can you help them?

Monsters:16
1x Dark Armed Dragon
3x Raiza the Storm Monarch
3x Caius the Shadow Monarch
2x Destiny Hero Malicious
1x Destiny Hero Dasher
1x Destiny Hero Plasma
1x Elemental Hero Stratos
2x Krebons
1x Treeborn Frog
1x Plaguespreader Zombie

Spells:16
2x Allure of Darkness
3x Destiny Draw
1x Reinforcements of the Army
1x Gold Sarcophagus
1x Emergency Teleport
1x Brain Control
3x Soul Exchange
1x Mystical Space Typhoon
1x Heavy Storm
1x Scapegoat
1x Smashing Ground

Traps:8
1x Call of the Haunted
1x Trap Dustshoot
2x Phoenix Wing Wind Blast
2x Bottomless Trap Hole
1x Torrential Tribute
1x Mirror Force

Extra Deck:15
2x Ally of Justice Catastor
1x Black Rose Dragon
1x Brionac, Dragon of the Ice Barrier
1x Goyo Guardian
3x Red Dragon Archfiend
3x Stardust Dragon
3x Thought Ruler Archfiend
1x Mist Wurm

Side Deck:15
2x Mirror of Oaths
2x Kycoo the Ghost Destroyer
1x Mobius the Frost Monarch
2x Light Imprisoning Mirror
2x Dust Tornado
2x Threatening Roar
2x Pulling The Rug
2x Dimensional Prison

Any fixes?

It looks like a decently made deck, although perhaps a little heavy on the number of Monarchs and not heavy enough on tributable material.

-1 Raiza
-1 Caius

You aren't using LJM and Mind Crush, so you don't need 3 Raiza. I'd even consider just doing -2 Raiza and keeping the 3 Caius.

-1 Soul Exchange

And that is minimum. People are already using Waboku and Threatening Roar mained, so with 3 Soul Exchange you will never have a Battle Phase where you can actually attack...consider dropping another 1 as well.

-1 Scapegoat
-1 Plasma

Plasma is only good to run in deck where you can use him with Trade-In. You have no other level 8 monsters here, so he's completely random. With him out, Scapegoat also loses its appeal here.

+2 Gravekeeper's Spy
+1 Gravekeeper's Guard

fodder for Monarchs while giving you an easy +1 or sending back a stronger monster like Stardust.

+1 Destiny Hero - Fear Monger
+1 Destiny Hero - Defender

4 D Heroes was already fairly low and I took Plasma out of the equation, so you need some more in order to be useful. Fear Monger works well with Monarchs, and Defender will be able to stick around for an extra turn most times to be fodder for Monarchs. All this also gives you a bit more choice when you summon Stratos.