With New Yorick no longer a viable proponent of Manamune and Muramana, that would leave Urgot, Jayce, Ezreal and, maybe, Varus as the only champions that would reliably build the item.
With such a small part of the champion pool needing access to that item, are there any plans for the eventual removal of the item from the game?
Any thoughts on compensatory buffs to the aforementioned champions, who are so dependent?
No, we've no current plans to remove Manamune/Muramana. They are only core on a few champions, which is a downside, they've got an interesting play pattern to them though and through offering delayed power give both an interesting trade off and a pretty healthy form of advantage. It also helps that they're the counterparts to the somewhat more widely used Archangels, so cost of having a low ish item line's somewhat compensated for there too.
So you thought Muramana/Manamune needs removing, and you literally ignored the fact that 
is still here.....
Just making Manamune charge up a fair bit more quickly would probably be enough. Something like 6 mana per charge rather than 4. Given the fact that most games are decided by 15 minutes an item that doesn't really kick in until the ~20 minute mark is a HUGE liability.
He still is? He still spams Q?
One small simple change puts it in the conversation for a lot more champs. Give it a 1% bump in how much AD you get from your mana. At full charge, it could be the highest AD boost in the game, Just as 
can give the biggest AP boost in the game other than 
. It may not have a lot of the other things that could make it sexy to AD champs, but simply having the highest potential AD boost in the game makes it more viable for a broader spectrum of champs. If you had 2000 for your max mana, you would get a total of 85 AD, rather than the current 65 AD total. If you are hitting a measly once per second that is a flat 20 dps before armor. Most champs with this item are likely to get closer to the 1.5 or higher attack speed range, increasing the effect even further.
Potential to make it much more sexy (imo)? Simple. Take the Shock effect of 
and bump the damage to 10% of current mana, but make it only go off every other hit. Again using the example above of 2000 max mana, you would go down to 1940 on hit and do 116 extra damage currently. That goes up to 194 extra damage if you bump it to 10%, but you only get it every other hit. Say you are attacking 1.5 times per second, not out of the question, and you use no abilities between six attacks. Currently those six hits would be (in 4 seconds) 116 bonus, 113, 109, 106, 103, 100 for a total of 647 damage (161.75 dps), and you would be down to 1665 mana (83.5 mana consumed per second). With the bump, you would be looking at 194, 188, 183 for a total of 565 damage (141.25 dps) and have 1826 (43.5 mana consumed per second) mana remaining. Overall you lose 13% of the abilities dps, but use about half as much mana to do said damage. This leaves you far more mana for using your abilities (which are going to do more to boost your dps than basic attacks anyway) at a fairly insignificant reduction of your dps when you look at the big picture. Also if the change to the attack damage boost above was made as well, you lose no dps, but greatly reduce the mana consumption of the item's ability.
It would wind up scaling faster than the current model as you bought more mana boosting items. I admit, it would still be a bit of a niche item for the more mana hungry ranged attackers and hybrid champs, but I think this would be a good rework of the item, and cause it to see more play, what do you guys think?
