A fifteen-page document covering numerous aspects of playing Moira, from the basics and her abilities to more advanced techniques. As with most Wawa resources, it is well-written and excellently organized.
This D.Va guide is more introductory, covering D.Va's basic abilities, role, and some character match-ups. At 14+ pages in Google Docs, it can hardly be considered "basic" though!
A long, detailed, and thorough text guide to Genji. Although this is an older guide, there is still a good amount of useful information contained within. Exact numbers may have changed, but Genji's role and abilities are similar.
Wawa's Boot Camp is an improvement-geared online boot camp, helping to connect coaches with players. They have also created a number of excellent guides.
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