Resist energy feat and essences

[Tarkus the dog]

How do these two work together, or do they work at all?

Would the DR go up to 10, or 5 and 5 separately or simply 5?

[TimeAdept]

The pre epic feat and the epic feat will both stack with items, but the feats do not stack with each other.

[Tarkus the dog]

Essentially meaning that the epic feat simply puts you to 10 and not 15, but with the essences it does puts you to 15?

Also meaning that the pre-epic feat puts you ( with the essence ) to 10?

[TimeAdept]

Pre Epic feat + essence = 10 DR

Epic Feat + essence = 15 DR

Pre Epic + Epic + Essence = 15 DR

[Tarkus the dog]

That helps, thanks.