Banci Ki said:
2. "To defend it's wielder from any attacks it cannot absorb"
3. That's why i say that if the Dovahkiin got hit by Enkidu it's the end. Also, can Enkidu touch intangible being?
We don't know if Dovahkiin actually struggle in his fight against Alduin, the 3 Nord heroes just want to join you. We don't even have a chance to talk to them. Alduin in Sovngarde is considerably more powerful than when we fight him at Throat of the world + the boost that he get when he closer to the end of the current Kalpa is pretty significant.
2.
To defend its wielder from any attacks it cannot absorb, the Shield lends him or her health. Don't cut words were it interests you, that's not a good move. Anyways, if the Shield can't absorb Ea and lends Dragonborn health, logically it breaks in the process because it couldn't absorb the attack.
3. It sure can. The chains bind the space around itself as shown when completely nullyfing the Command Spells which is magecraft very close to the True Magic. Also if it couldn't, every Servant and their mother would avoid it by going in Spirit Form. Don't bring up points that are already debunked.
Also Alduin's stats are reflected in his page and are nowhere near close to tier 2 when he fought Dragonborn. Dragonborn is supposed to struggle against Alduin because that's the more logical thing to do. He's not going to just stomp his archenemy to the ground, it's fiction, it's supposed to be cool.