I need help with a pair of artifacts!

[MonkeySage]

I have here a CL11 Artifact Elixir which grants one of a number of effects to the Alchemist that drinks it, based on the Alchemist's needs- The effect is permanent, but the elixir can only be used once in a lifetime.

I'm trying to think of what effects the Elixir can grant: I'm calling it the Elixir of Alchemical Insight.

Effects I've thought of so far-
Extra Bombs per Day (how many?)
Increased physical boost from Mutagen (by how much?)
???

The second one is a tuning fork, given to the bard- same CL. It functions as a rod or wand which can directly increase the bard's offensive capabilities- and can also be used as a shortspear, sized for a small creature like the party bard.

[PairO'Dice Lost]

While boosting damage and extra class feature uses is handy, ideally artifacts should have fairly impressive and unique effects to distinguish them from run-of-the-mill magic items. So I'd try to come up with some benefits that aren't achievable by any other means in the game, or at least would otherwise be quite rare and difficult to achieve.

For the alchemical one, I'd look to traditional alchemical lore for inspiration. There are a couple of iconic effects that the elixir could achieve directly (eternal youth or some other sort of mental and/or physical transformation to "perfect" the drinker) and some iconic bits of knowledge that it could grant the drinker (how to transmute base metals into more valuable ones, how to achieve magical effects in an alchemical--and therefore instantaneous and nonmagical--way, and so on).

For the bardic one, tuning forks are generally themed around bringing something into tune with a reference note, so I'd think in terms of thematic "resonance" with things. You can focus on the gish aspect given the shortspear association (let it resonate with an opponent's armor/shield/skin/etc. to lower or bypass AC and DR, add sonic effects when the bard hits someone as it resonates with their body, etc.) or more on the "magical offense" aspect given the rod association (let it turn any spells into sonic spells as it resonates with their verbal components, counter or de-prepare enemies' spells as it mystically "resonates" with the magic in their minds, etc.).

In general, think of the kinds of things you'd hand out as awesome and flavorful prestige class capstone features (or, since this is PF, high-level archetype class features), in flavor if not necessarily in power level. You might want to look at some alchemist and bard archetypes on the PFSRD for more ideas along those lines.

[MonkeySage]

I'm still kind of stumped. Trouble is, the effects need to be useful in combat. I could adjust this to "wondrous items" rather than true artifacts...

The tuning fork is a good suggestion for t his purpose- i'm still stumped on the elixir.

I'm still set on the idea that the elixir's powers can vary depending on the alchemist's needs... That it affects one of their class features.

[aimlessPolymath]

I'd say it instantly grants the alchemist a new Discovery (maybe two)- maybe not of their choice, but one that is useful at the time.

Perhaps they can choose: one of their choice, or the DM chooses two?

What the alchemist needs in the moment is what they get. There are a number of fairly niche discoveries that could be provided in this way: Fighting a rogue? Preserve your organs on the spot! Fighting an ooze? Ooze Blight suddenly is relevant!

[Segev]

Well, there's always "it grants perfection," with the idea that a "perfect" being has 18s, pre-bonuses, to all stats. So, to get an average being there, it gives +8 alchemical bonus to all stats.

You could have it grant immunity to poison and disease, and fast healing 5.

Perhaps it makes him know all of his formulae inherently, making him only need a formula book as a place to work it out initially (spending money to scribe it in). No need for it after that, as he has it perfectly memorized. Moreover, his superior knowledge and technique lets him use almost magical means (perhaps he claps his hands together and then touches the vial) to prepare extracts: it takes only an action to do so.