I think we're overcomplicating this. Should be a very quick and easy instance.
1. Before you enter, buff up. Get 5 minute ISS Domi and SWS/Spectral Dancer buffs. (I don't mention Prophet because we already get event buff.) For those of you who have enchanted your Eva Saint melee/range attack buff for +Might or +Magic, go ahead buff that, too. If you use Soup, sure, add that, too. You keep those when you're in Golem form and they do help damage stats.
2. Create a basic macro with the two golem skills and put it in your Auto Target box. Make sure you choose Short Distance Auto Target. Use this at beginning for the mobs only. Remember, those mobs actually restore your HP and MP when you kill them in Golem form. (I'm still trying to figure out how people die in this instance at that stage.)
3. Also put the 2 golem skills on your hot bar. Lurin always appears at the 3-minute mark. Make sure you're close to his spawn point to save time. When Lurin spawns, turn off your Auto Target macro, manually target Lurin and then right click on your hot bar golem skills. The important thing is to make sure that Lurin is the only mob you've targeted. Don't worry about the other mobs. Your sweep golem skill will AOE kill them and replenish your HP even as they are attacking you. If you have half decent equipment, you should easily kill Lurin in the three minutes.
It goes without saying, you can build a single macro that does all of the above for the entire duration of the instance, if you know how to create them. Not giving away all of my secrets here.
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If you have really low gear and don't kill Lurin before your Golem transform expires, BSOE. Be happy for the boosted XP that you get from killing the other mobs, but you can't really finish the instance because Lurin will kill you easily in your normal form with one hit. You can debuff/slow him, you can try to kite him, but eventually he'll catch you and you're dead.