Borreload Savage Dragon has some of the best effects of any Dragon-type synchro monster , and it synergizes directly with the Dragon Link strategy
Shooting Star Dragon can stop your opponents attacks and card effects, plus attack as many as 5 times per turn
It's a soft once per turn effect, meaning multiple copies can negate multiple Spell cards
Although it will vary from deck to deck, this one seems preferable to the machinations of some of the other high-priced options
If you still want to run them, try to pick the ones that put you in a card advantage if resolved: you're still gonna have to banish stuff for Gullveig after dealing with the opponent's board
While the Extra Deck is limited to 15 cards, often these aren't chock-a-block with repeat copies, as tends to be the case in the main Deck