Ensnare
Ensnare is a rechargeable trinket torn from Uber Echidna — and it is the only item in the game that affects PvP.
Every other trinket on Ancients carries some version of "does not affect PvP" in its lore. Lamia's Veil says it outright, and that has been the house rule for every trinket since. Ensnare is the one deliberate exception, hung on the hardest content on the server.
What it is
Right-click to fire it. It's a control item, not a damage one: it adds no damage whatsoever, and it can't make you win a fight you were losing. What it can do is decide whether a fight happens at all — the standing complaint about open-world PvP in the mine is that everyone simply runs.
Exactly how far it reaches and how long it holds is left for the arena and the mine to teach you.
Charges
It runs on the same rechargeable frame as Lamia's Veil and Echidna's Strand: click Ancient Energy onto it to charge it, and each use spends a flat amount. The current charge count is shown in its name and lore, so you always know how many shots you're carrying. There's a cooldown between shots.
It can't be sold, and it doesn't stack.
Where to get it
Uber Echidna, and nowhere else. It's her unique — the rarest thing in her table, and the one drop no other uber pays.