The Tavern

I'm in no way married to the name. Here's the idea: an unrandart +5, 17/17 rod that functions as an antimagic weapon (this is mostly relevant for suppressing the player's MP, as rod melee is not a good way to actually apply antimagic.) It has three spells:

a) Silence
b) a level 6 spell Bolt of Antimagic. This would be a moderately damaging bolt spell (maybe unbounced Lightning Bolt strong) that applied antimagic damage to anything it hit.
c) a level 8 spell Mana Explosion. This would do ac-bypassing damage to all casters in LOS. It should also set the player's MP to 0, doing some modest ac-bypassing damage per point of MP consumed (1d4 seems okay to me.)

Alternatively, this could just be a normal rod; the likelihood that somebody would find enough of them to be able swap multiple in is quite low.

I think (hope?) that the current direction for rods is to make them all have one, unique effect (like inacc and lightning rods) and possibly be evocable from inventory without wielding.

It sounds like that's probably the case. I don't really get why that would be, or what the problem is with current multispell rods (is it just the interface?) elliptic mentioned in crawl-dev that he finds rods duplicating existing spells to be boring. I can see that, although I personally don't find that boring. I generally feel that rods fill a slightly different niche, even when they are just duplicating a spell. Bolt spells from a rod are unlikely to ever be the centerpiece of your offense the way that similar spells might be for an elementalist. (EDIT: Clouds on rods are a different story; as much as I love abusing those they should probably go.)

I'd say C sounds pretty interesting for a single effect rod. 4x MP could be a ton of damage, though.

Do monster spells have levels? What if it rolled XdHD damage, where X is the highest level spell known, and HD is the HD of the enemy. Use character level/2 instead of HD for the player.

Rods are pretty bad interface-wise IMO, yeah. Wielding, unwielding, choosing spells requires a lot of keypresses.

I like the OP's idea, including as written (though 1d4 damage per MP might be high, yeah). But if necessary ackack's basic idea could easily be tweaked, as per what Sar says above:

Can be evoked while wielded to apply an antimagic effect to everything in LOS, including user. Power of antimagic effect is evocations-dependent. You can hit enemies with it to deal damage, similar to rod of striking, to enemies who cast spells; each strike takes 1 charge. (Also applies strong antimagic effect to such enemies.) This makes it kind of a mix between rod of striking and lightning rod.

Or:

You evoke it from inventory without wielding, and it applies an antimagic effect to everything in LOS, including user. Power of antimagic effect is evocations-dependent.

I think rods would be vastly more interesting if they all had the rod of striking ability added to whatever spell(s) they had, then wielding them generally would be a reasonable choice, and using the charges for melee or for the available spells would also be an interesting choice.