This item is one of my absolute favorite's of the season 3 items.

the only thing I think needs to be changed is the fact that it builds out of a sapphire crystal. It already has the chalice passive, do you really need the extra mana?

Should there be a replacement, or should nothing be added, and in turn, lowering its buying cost??

Idk what else they would put for it. I don't think its bad since mana synergises with % mana regen.

I wouldn't mind seeing another defensive stat on it, but otherwise I think its great as it is.

It's a pretty good item, but really seems pointless to build that extra saph so I never really end up wanting to complete it. I end up using it as a reason to buy chalice so i can spam.

Crucible needs 1 of 2 things, either:

A) Instant speed on the Activate.
or
B) Tenacity added to it.

A) Just for the target of the active though, otherwise its another shureleries

B) Tenacity for supports would be nice, granted there is merc treds but i've only ever seen tank supports buy those

Mana is not an issue for the item. I've had good use on TT with Warwick, I build him as sort of a Mana Hybrid.

Merc Treads
Muramana
Frozen Heart
Wit's End
Michael's Crucible
Frozen Mallet

How about another Null-Magic Mantle? (Like how Landry's Torment work.)
On the other hand...it might make it one of the strongest Magic Resist item, static wise.(So far it's Runic Bulwark with 60MR, following by spirit Visage's 50)
Besides, it already provide 40 Magic Resist right now.

Mana manipulator might be a good replacement too? (Saw some requests from other post)
But then it will be a must buy in ARAM for a team that is mana dependent...

What if we just upgrade it directly from Charlice without other ingredients, just the combine cost?
However, it might be too easy and early to counter a heavy crowd control opponent...(15 minutes and a Vayne gets Cleanse, QuickSilver Slash, and Mikael's Crucible...How does that feel when you main Malzahar, Malphite, Blitzcrank...etc?)

I think the straight answer would be "Nope, Mikael's Crucible doesn't really need that extra mana." (Like most of the summoners here agree)

Consider Ruby Crystal or Kindlegem then? :P

I would like to see some health and/or more MR. Make it an attractive alternative to banshee's/odyn's veil for a more mana-hungry champion who doesn't need the offensive boost from athene's. Keep the mana tho, Ryze and Singed will thank you.

I really really like this idea. But the problem is that the aura wouldn't stack with Shard of True Ice. Considering both are supposed to be support items it would be counter productive to create 2 items for mana based supports that do not work with each other.

And that's different from the way it is already how?

It's hard to figure out what to use to upgrade it.

Many of the other tier1 items just plain don't fit the item. Longsword, dagger and brawler's glove make it an AD item (though not so much dagger but still heavily AD leaning).

You can't really use amp tome or blasting wand without adding AP to it, but then that's what the Grail is for.

As mentioned by others, Null-Magic causes the item to have more MR than virtually any other item in the game.

Ruby crystal could cause balance concerns considering that Ruby Crystal and its upgrades are already components in a large number of "support" items (Sighstones, Aegis, Surelia's, etc) and could contribute to making supports tankier than intended

Other than Sapphire Crystal, the only real options are the following

* Mana Manipulator/additional Faerie Charms
This would probably be the ideal option instead of a sapphire because instead of working against the passive by creating a larger mana pool, you actually work with the passive by increasing the mana regen rate that the passive functions off of

* Rejuvenation Bead(s)
I would have personally liked to see 1-2 rejuve beads instead of the mana crystal and given the item a health regen affect similar to the mana regen passive. I.E. increasing health regen based on either missing health or even missing mana/mana regen rate