Me and some friends came up with 3 ideas.

The first is some new weapons.There are 7 of them for each status and they each have a different design and a different Charge.For example the shock weapons charge could shoot a ball of lightning and all the enemies around it get hit so a bit like a chain reaction.The weapons are...

Fire=Club of Vanaduke
Freeze=Blade Of Maulos
Shock=Scepter Of The Twins
Poison=Toxic Dagger
Curse=Scythe Of Margel
Stun=Hammer Of Wrath
Finally......
Sleep=Trident Of Drowsiness

The next thing is a Tier 4 in the core but the thing is you would need something called heat resistant armor it makes you completely immune to fire and since the core in the real world the core is a giant ball of blazing fire it would make sense.

Finally I have saved the best for last the new 9 bosses i came up with,Here is the story.One day the 9 heroes took a day to the core to see the squad but on their way,near the core,the had found a large pile of dark matter and corrupted their souls! the only way now is to deteat them in a battle.for 1 week you have 7 days too fight one of the 9 heroes and they will chande every week.Here is they're equipment

Jorin=Leviathan Blade,Valience,Nitronome,Aegis,Azure Guardian Set.
Daxen=Nova Driver,Storm Driver,Hail Driver,Umbra Driver,Shadow Sun Set
Remi=Big Angry Bomb,Dark Matter Bomb,Shivermist Buster,Volatic Tempest,Bombastic Demo Set
Echo=Dread Venom Striker,Wild Hunting Blade,Final Flourish,Swiftstrike Buckler,Skolver Set
Izola=Sudaruska,Triglav,Iron Slug,Cahllahan,Ironmight Plate Shield,Ironmight Plate Set
Zebulon=Divine Avenger,Gran Faust,Dragon Scale Shield,Deadly Virulisk Set
Archilus=Glacius,Voltedge,Combuster,Grey Owlite Shield,Divine set
Walkon=Furious Flameberg,Fearless Rigadoon,Sentenza,Argent Peacemaker,Royal Jelly Shield,Royal Jelly Set
Sylvin=Achereon Gran Faust,Umbra Driver,Sentenza,Dread Skelly Shield,Dread Skelly Set

Hoped you liked my ideas i spent alot of time on this i even had to log on too spiral knights to talk to the heroes.Thank you for reading.