hi, ive never really made infernity b4 and i read the tips maria and cage gave which btw was outstanding tips but now i have one spell/trap to place

Monsters

3x infernity beetle
2x street patrol
1x infernity mirage
1x infernity necromancer
2x infernity archfiend
1x plaguespreader zombie
1x dark grepher
1x infernity general

Spells

1x recycle
1x dark hole
1x infernity launcher
1x wave-motion inferno
2x mystical space typhoon
1x pot of avarice
1x monster reborn
1x heavy storm
1x one for one


Traps

1x Curse of royal
2x dark bribe
1x transmigration
1x solemn judgment
1x solemn warning
3x infernity barrier
2x infernity break
2x infernity inferno
1x mirror force
2x call of the haunted
1x starlight road


Extra

1x Hundred eyes
1x void ogre dragon
1x infernity doom dragon
1x red dragon archfiend
1x red nova dragon
1x stardust dragon

thats my deck atm i need help on what spell/trap i should finish main deck with and what other 9 monsters i should put in my extra deck

Hm, I suggest that you make some changes...I'mma bold the changes in case I get wordy.

I haven't honestly played Infernity in a while though, so feel free to ignore anything until someone who plays it more often comes by. First, there are plenty cards I feel are just either lacking or unneeded in Infernities.
Cut out all:
-Infernity Beetle
-Infernity General
-Recycle
-Wave-Motion Inferno
-Pot of Avarice
-Curse of Royal
-Transmigration
-Mirror Force
-Heavy Storm (Unless you find it does not hurt your backrow usage)
-Red Dragons(may as well keep if you keep beetle)
You shouldn't have to dump in infernities, especially not for the sake of dumping. Beetle is unneeded, Recycle is slow, pot of avarice removes your monsters from where you want them, and there are better options than curse of royal. Inferno is questionable is well, but they should be left to your own experiences with it.

Next, some cards are a MUST:
+1 Infernity Archfiend(Key Card!)
+2 Infernity Necromancer(Key Card!)
+1 Infernity Avenger (Key Card!)
+1 Dark Grepher or Armaggeddon Knight (These are the best dumpers)
+1 Foolish Burial (Fastest & easiest dump)
+1 Call of the Haunted (Revival)

Further additions I suggest:
+1 Hundred Eyes Dragon
+ 2 Dimensional prison or have 2 Mirror Force (preference)
+1 Reinforcement of the Army (fetch grepher or armmageddon)
+ 2 Torrential Tribute
+2 bottomless trap hole
+1 Stygian street patrol
+1 Lavalval Chain (Amazing support card)
+1 Leviair (Street patrol abuse, and things eventually get banished)
+1 Ally of Justice Catastor
+1 Scrap Dragon
+1 Stardust Dragon

here is my infernity v2 recipe

monsters
3 infernity archfiends
3 infernity nercomancers
2 infernity avengers
2 infernity mirages
2 tour guilds of the dark world
1 stygain street patrol
1 Armageddon knight
1 dark grepher

spells
2 pot of duality
1 reinforcement of the army
1 mind control
1 infernity launcher
1 heavy storm
1 foolish burial
1 monster reborn
2 mystical space typhoons
1 book of the moon

traps
2 infernity break
2 infernity barrier
2 infernity inferno
1 solemn judgement
1 solemn warning
2 bottomless trap hole
2 call of the haunted
1 d. prison
1 starlight road

extra
1 infernity doom dragon
2 100-eyes dragon
1 void ogre dragon
1 stardust dragon
1 scrap dragon
1 armory arm
2 stygain sergeant
1 39 utopia
1 photon papilloperative
2 wind-up zenmaines
2 leviair the sea dragon

actually the first one u did was a red nova fun build but if u want to unlwash infernitiea deadliness second one\avenger hundred eyes loop...just saying lol