Sea of Stars

The relic is located in the “Throne of the Forgotten Queen” location; you will find it when you complete the additional quest for the battle with the Goddess of Cannons.
In NG+, use your save and immediately activate the “Cunning Gambit” relic with all the others except the “Dubious Call” relic, which increases damage taken by 40%.
Playing NG+ with the Tricky Gambit activated is fairly easy, provided you already have the best gear.
The Leaf Monster boss will drop a trophy.

The trophy is apparently glitchy, because in the main company I killed 8 bosses (Lou Zhugg, Spectral Reaper, Erlina, Euforul from Flashmancer's fortress, Sea Slug from Dokari ruins, the second paradise killed Romaya, the Queen of Cannons and killed the Ancient Mist for the second time). According to the idea, the trophy should have fallen on NG plus during the battle with the Giant Slug, or at least on the ancient fog if the Golem is not considered a boss at the beginning. In general, the trophy dropped after I killed the boss after I came to the city of Breeze.
If anyone is interested in playing against bosses with this relic and not running through ng+ with one hit, here’s how I proceeded. Be sure to put the Reaper's Mercy ring on the characters (with a lethal blow, if the characters have more than 50% HP, they do not die but remain in one hit point) with the gambit turned on, any missed blow will be lethal and the characters will always have more than ten HP for the effect to work. I also put a silver ring on Vallerie that restores 10% of HP from damage and this healed her completely. One character can always be on the field. Also, don’t skimp on using a lunar shield so that you can survive another blow if the boss hits with a single attack, this will also make your life easier and you won’t have to learn timings. Give Serai a ring that gives +1 to mana or -1 to the cost of spells so that you can use disorientation as often as possible when bosses cast spells. Don't rush to waste combos. Sometimes it can be useful to effectively disrupt a cast. But if you choose the right moment, it’s better to use the Arson combo (3 units of the Zeil Ri-Shan combo), it gives a lot of damage if you control the tornado, I consistently had 600-800 damage. On the big bosses there are even more than a thousand. And Ri-Shan’s best super blow is if he steals anything and works like Serai’s Disorientation so that there is more time to recover and deal damage. Living Mana - it’s better to have two consistently on the field, the third on CD can be used when attacking. But no one forbids charging all three spheres at a well-chosen moment and hitting harder. But I played it safe.
Another must-have relic could be a magic pocket. Allows you to use food once a round without wasting a turn. I consistently cooked food with mana so that I could again use Serai’s skill, and if other characters didn’t have enough, with rare exceptions, I gave them mana, but such cases were few. I also had a couple of pieces of resurrection food with me, just in case, but spoiler, it wasn’t useful.
Of the bosses in the main game, I found the spectral reaper a little difficult, because he summons copies of himself and attacks at the same time. And Euforul was stuffy. It took me a while to get the hang of the extra step.