My first item suggestion would be a type of mana steal item.
It's stats could be easily changed but I would suggest the original item being implemented into the game much like the standard lifesteal at 900 gold but give 13% of your damage is returned as mana.
It would also be a part of a two recipes that would be an alternative to helm of the dominator and satanic. or abyssal skull and whatever satanic is named.
the first I would suggest being named helm of essence would require of course the mana steal item and ring of the teacher. It would give 18% mana steal 4 armor 75% mana regen and +9 to damage.
This would then be a part of a recipe I would suggest be named Sole Headress which would combine Helm of Essence mystic staff and a headress of rejuvination. It's stats would be a 20% mana steal 4 armor 8 health regen 100% mana regen and a use effect to remove half of your current mana dealing that much damage in an aoe around you that would be divided by the number of targets effected and slowing all targets by 25% move speed or a 1 second stun if another aoe int item slow isn't needed due to shivas.
The Goblin Mortar
My other item suggestion would be an item that would turn a ranged attack into a small splash damage attack. The splash damage would be based off of your primary stat and would do that much damage around the primary target. The damage could either be exactly the number of the stat or a working of that in some way. The requirements for it would be an ultimate orb and any of the 3 +10 and +25 to a stat items.
The stats of the item would be +10 to all stats, +45 to your primary stat, the splash damage effect, and a use to backfire the item knocking you back several yards. (I would also like to have a golden text or whatever it is called for this item that said "only goblin engineering could involve purposefully backfiring your own weapon." or something along those lines
Of course all of these items could be modified but I have always liked the ideas of these items and would like to see them implemented into the game
I apologize for any mistakes and my poor knowledge of the names of HoN items. I haven't been able to play enough to memorize them all yet but I'm sure I will
Thank you for reading.