I know the way to beat the "leech lord", if you are talking about the one that surrounds and traps you. you want to take out its minions with snipers and slowly cut off its arms. The more you cut off the arms the less minions it can summon until it cant summon minions any more. Then just go straight for the head with snipers to remove the leeches and slowly dig into the boss untill his head is vulnerable, then just rush the core. Hope you find this helpful!