Ffraegar also boosts normal attack crit rate and damage and works well with Syndrion and is the absolute best pairing you can run here for marksman and even on the top in general. They both enhance each other so much and if you run their artifact you will give everyone a hard time

Goldcrest is an amazing marksman artifact with Syndrion and you will deal incredible damage doing so + the overall Marksman unit buff is also out of this world, too