I give it a 7.5 out of 10.
It was an average MCU teaser.
Ominous but also kind of subdued. Outside of some cool snippets like that Scarlet Witch shot and the Strange variant at the end there wasn’t much to go on about. I guess the saw blade spell was a nice touch as was the 3 headed dragon spell plus 1 or 2 interesting/mind bending shots.
I felt there was a lack of footage and a substantial amount of black screen sprinkled throughout, enough to be noticed which made me raise an eyebrow over it. I went and checked it out and out of a 2 minute and 11 seconds teaser there was 27 seconds of black screen, 7 seconds for the Marvel logo and 11 seconds for the title treatment, so a total of 45 seconds of not much on screen + 86 seconds of footage. Seemed a bit odd.