Obviously, angels almost always have flying, so Errant and Giada works very well with them
He is using a combination of the Speedroid engine and Dinosaur engine in his Zefra build
A blockier frame and white text for the card name and card type are iconic of older Magic cards
Kaldheim brings with it new keywords such as Foretell, which allows you to exile cards from your hand to play them later for slightly cheaper, and Boast - which is a lot like the Raid mechanic from Tarkir, but this time around you can use special effects on cards for a different cost
They have differing usefulness of course, but can all put in work
These days it has been pushed quite a bit lower and is rather overlooked due to having being around in basically every format since the dawn of time, er, magic