Energy kits when entering Gore-blin

[Azerothraven]

When the portal spawns, Do I need to use 3 energy every time to go to his layer.

[Cons]

No. As long as you have the altar relic you're good to go.

[Iseenoobs]

Only one member needs to open the portal then the rest of the party can join. Not sure if you can invite others if they are in different zones while you're in the bonus map. Someone must confirm this one..