List noob: Help with Colloseum

I’m playing a game against my filthy Custodes friend on Friday and to be honest I always lose against him… we’re playing a 650ish pt Colloseum game on Friday and I want to tryhard against him.

I’m really shit at building lists and when I search for lists I only find stuff I can’t run. Can someone have a look at this list I threw together and give me an idea if I’m in with a chance?

Nurgle’s Bane (660 Points)

Virulent Vectorium

CHARACTERS

Lord of Contagion (145 Points)
• Warlord
• 1x Manreaper
• Enhancements: Furnace of Plagues

BATTLELINE

Plague Marines (190 Points)
• 1x Plague Champion
◦ 1x Plasma gun
◦ 1x Power fist
• 7x Plague Marine
◦ 1x Blight launcher
◦ 4x Boltgun
◦ 1x Meltagun
◦ 7x Plague knives
◦ 1x Plague spewer

OTHER DATASHEETS

Deathshroud Terminators (160 Points)
• 1x Deathshroud Champion
◦ 1x Icon of Despair (Aura)
◦ 1x Manreaper
◦ 2x Plaguespurt gauntlet
• 2x Deathshroud Terminator
◦ 2x Manreaper
◦ 2x Plaguespurt gauntlet

Myphitic Blight-haulers (100 Points)
• 1x Bile spurt
• 1x Gnashing maw
• 1x Missile launcher
• 1x Multi-melta

Poxwalkers (65 Points)
• 10x Poxwalker
◦ 10x Improvised weapon