Now that Rod of Carnamagos has been ruled to act like a stick-shaped Olive McBride, here are some cards that interact with it. I've grouped them by what type of chaos bag you want, as the token distribution will affect the probability of revealing the token you want. If you're doing only or no-/, you don't need the upgraded version (though the Level 0—now chained to 2 xp—is only 1 per deck).
I'm not including interactions that are obviously bad, like Shrivelling and (added) Old Hunting Rifle.
bag
- Armageddon, Eye of Chaos, Shroud of Shadows: Perfect synergy with the Rod, and as a bonus you actually use the Rod for what it was originally intended for.
- Curse of Aeons: Yes this card sucks, but there is a niche case where you’re fishing for a in a heavy deck to activate a -specific card effect. Note you don’t remove the tokens until the end of the test so they can still come back to bite you in Step 3.
- Prismatic Spectacles
- Control Variable
- Fey: Use Rod on the first free trigger window before Step 2 when you commit skill cards. If a is revealed, you know that retrieving this card is guaranteed.
bag
- (edited) .35 Winchester: I am now unsure if revealed by the Rod trigger Taboo Winchester's bonus damage as the FAQ says tokens revealed this way have no modifiers. Non-Taboo would still trigger if a 0, +1, or were revealed by the Rod.
- Blessing of Isis: Useless as the conversion happens during the trigger window where it does nothing.
- Jacob Morrison
- Beloved: Like Fey, use Rod on the free trigger window before Step 2 to see if a is revealed to guarantee the auto-succeed if you commit.
- Guided by Faith
- Blessed Blade (level 0 version)
- Miracle Wish
Non-/ bag as those tokens dilute the chance of pulling other tokens these cards want
- Song of the Dead
- Jim's Trumpet
- Shards of the Void: The Rod allows you to get both bonuses from the spell with the same token, as you seal a 0 token in the free trigger window for +1 damage, which results in a +2 bonus during Step 3.
- Sixth Sense
- Storm Ruler: Weirdly designed card in that if you don't use with the Rod, it's not really worth the xp cost, but if you do use with the Rod, it becomes a bit overpowered.
/ bag
- Jewel of Aureolus
- Ritual Candles: As per the FAQ, this triggers EVERY time a symbol is revealed during the test since it doesn't exhaust. You can stack bonuses during the Rod reveal because each revealed symbol nets you a +1 to the Step 3 skill test while their (usually negative) modifiers don't apply.
- Wither: Final Chapter 1 Taboo now lets this trigger with /.
- Upgraded Spectral Razor, Read the Signs, Ethereal Form
- Banish: The bonus effect is sort of meh though.
- Tristan Botley
- Eye of the Djinn
- "Lucky" Penny: Sort of a funky interaction as it doesn't exhaust. That means it triggers during the Rod reveal and again during Step 3. Depending on your reveal and coin flips, you might pull a bunch of cards with this.
- Living Ink with Macabre Description upgrade
- Seal of the Elders: Also works with either servant
- (added) Token of Faith: The Level 0 is not Blessed so Kōhaku can't take it, (edited) but he can take the Level 2 version.
- (added) Paradoxical Covenant: Based on a comment below, I now think this does trigger with the Rod, greatly increasing the chance of auto-success.
- Broken Diadem: Good for summoning Twilight Diadem but once you have it, that card's ability to proc an is useless during the trigger window.
- Wish Eater: Useless as the /// token has no intrinsic effect so why cancel it, unless you REALLY need that healing effect.
Other interactions
- Premonition: Great synergy with the Rod. If you pull an or something else you want, don't trigger the Rod. If you pull a or something else you don't want, trigger the Rod to "dump" it so it doesn't mess up your Step 3 token pull.
- Prescient: Also great synergy. You can count the tokens to see which type you have most of before guessing (though this will probably be "symbol" in most cases).
- Confidence: Also great synergy as the Rod guarantees this gets max boosted.
- Recall the Future: Not as good synergy as you need to specify a specific token. Unlike a skill card, you must activate this at the beginning of the skill test, so you can't cheat and use the first free trigger window to see what tokens you pull first.
- Unrelenting: You can use this to seal tokens you don't want revealed before triggering the Rod.
- Other Covenants besides Paradoxical: Works but useless.
As a reminder, revealed tokens from the Rod only trigger card effects. They have no intrinsic effects on their own, so revealing 2 tokens with the Rod won't screw you over (and actually helps you for symbol-triggering card effects).