It is easy. There are many people doing LB run. They will pay effort to achieve the top LB rank by keep playing the event. Thus, they are most likely Plat Tier. Party with them and let them enter the portal first. Then, most likely the Syrillax or Big Rock boss will be appear for you to kill and get more point to reach higher tiers.

The point is that you need to have good friend or guildmate willing to party with you.

lastly, energy cannot be stack in stash or neither transfer (the crafted one). Even you run with other character, you cannot transfer the energy to the primary one. That's why so many player complaining the crafting time of the energy. If they can use multiple character for crafting, then no more problem.

Hope it can help