Legend Path Gray Garrison final encounter

[Lahoo Eckbert]

What's the strategy here? My party is lvl 17, Am I too low to do this encounter?
I start the fight with every buff available to me but I get wiped in 4-5 seconds.
Party is MC(rogue thug 13 assasin 4) darean, seliah, regil, nenio and arueshalae.

Is there like a cheese strat here? Like a special item or something? If all fails I'm willing to use any exploit. Not enjoying Act V too much.

[Darth Vendar]

displacement, stoneskin, heal and some level 7/8 summons for fodder. true seeing. I had a custom merc party and it took two tries to get it done. my party was a fighter {aldori defender}2 rogue 16 mc,, figt2 grenider alchy 16, fighter 2 cleric 16 , fighter tower shield spec, 18, zen archer 18, fighter 2 spell master wizard 16, I believe the best way is to have the wizard with ascendent element and then cast those types of spells { i use the bracers from blackwater to turn everything to electricity and with ascend elec no immunities/dr.
then if you are still getting wiped use toybox mod and up your weapons/gear.

[Serchine]

Yeah that fight can be a little tough, There are 3 enemies, two of them standing by side are neutral outsider which means you cant smite them, and they have high stats.

However you only need to kill the one in the middle, the other two vanishes automatically afterwards. Also he's evil, which means you can smite him. just focus everything on it, ignore others, make sure he dies before the other two wipe your party out.