I'm looking for any sort of ability to add onto an intelligent magical lance that will allow it to change into other weapons. Whether this is something like making it "wear" a ring of Polymorph Any Object to an ability like Changeling for Spears. Biggest reason behind this is that... well... noone uses bloody lances in the party. It also doesn't help that the one character without a melee weapon is kinda small to be trying to wield a medium sized full jousting lance (he's still a medium sized creature, but weak and small). Also, this is going to be considered an independent character unless being wielded by someone, it can take class levels, so if a class has something particularly in an early level that might somehow be of use, let me know.
The Changeling enhancement (MIC, p.31) allows the enchanted spear, shortspear o longspearlance to change to a spear (two-handed), a shortspear (one-handed), or a longspear (two-handed) sized appropriately for you.
The Morphing enhancement (MIC, p.39) turns your changeling weapon into a weapon of your choice, but must be of the same size and type (light, one-handed, two-handed).
Using both in this order allows you to morph a spear into any non-light weapon of your size. Using these in the opposite order allows you to turn a lance into a spear and then use changeling on it.
The Sizing enhancement (MIC, p.43) further adds versatility, allowing you to get a smaller weapon so that you can use it as a light weapon (with a -2 penalty to hit) or a bigger weapon to use with feats and class features intended for wielding oversized weapons.
Give the weapon the Morphing enhancement, from the Magic Item Compendium (page 39).
The enhancement allows the wielder of the weapon to change it into another weapon of the same size and type as a standard action. I think it'd be reasonable to allow an intelligent weapon to change itself.
If your sole reason for the shift is so that a non-lance character can claim it, just give it an extra story-based ability to change its form once per wielder. There's no reason to use up a property or enhancement unless you want it to have the power to change on the fly. It's already an intelligent item; they're allowed to break the rules a bit.
An old question, but it surprises me that no one brought up the Rod of Lordly Might.
Turning the item into a full Rod of Lordly Might is probably overkill.
However, its primary function is swapping between weapon types (and magic traits) at the press of a button.
I don't know what the abilities of your lance are (except intelligence) so, as an example, you could allow it to switch between:
- Spear/Lance : +1 Wounding
- Javalin : +2 Returning
- Mace : +1 Flaming Ghost Touch
- Long Sword : +2 Frost