mana scs and an insight swap might make fire work, but id still say it will be worse than an echo strike lock.
i havent done any pvp, so im not sure how lock's stuns are performing yet. like apoc specifically.
edit: now that i think of it echo would likely use insight anyways. fire = spirit im sure.
havent and dont plan on dueling w a lld lock but echoing would win
just did maxroll with basic gear rolls ike 2chaos/20fcr helm, 2chaos/3rof book, sojs viper mages etc 1 pointed the 3 to get blade warp, rest rof+synergies still leaves 1 extra point thats useless
damage comes out to 772-996
so add the 5% per yard + max range of rof(idk what it is, i think its probably 12 or so) and its still weaker than fireball i think lol