4Game

Minus scepter and shard upgrades, here are some mechanics (correct me if im wrong) that are present in game but are still not available as a purchasable item:

• Health freeze (AA ult)
• Shatter (AA ult, axe ult)
• Cast range reduction (bane enfeeble)
• Track/single target exposure (BH track, slardar ult)
• Free pathing/flying movement (WW aghs, DK aghs, brood 2nd)
• Untargetable (Willow 2nd, book of shadows)
• Fear (Willow ult, SF ult)
• Taunt (WW ult, LC ult, axe 1st)
• Unkillable (Dazzle 2nd, troll ult)
• Mana steal (Invoker EMP, Pugna ult, Lion 3rd)
• Mana restore manipulation (Necrophos 2nd)
• Shared damage (Warlock 1st)
• Shared spell/status (Grim ult, earth spirit ult)
• Tree walking (treant innate ability, hoodwink 3rd)
• Vision reduction/forced vision (hoodwink 2nd, bane 3rd)
• Sleep (Naga ult)
• Day/night manipulation (luna ult, NS ult)
• Barrier/path blocking (Shaker 1st, tusk 1st)
• Damage steal/drain (razor 2nd)

Obviously, some would be unbalanced should they become a purchasable item. Some may even render heroes obsolete of course. What mechanics would reasonably be added to the game as a purchasable item?