With the soon-to-be-release of Guidemasters Guide to Ravnica (D&D 5e's version of M:tg), this publication goes a long way to possibly filling in gaps that many of us see the 5e version not going far enough to fill.
The one area of concern is that WotC writers have stated that the spell system will continue to be the same, even through M:tg relies on a 5 colour magic system centered around Mana. The system within goes part of the way to dealing with that (Variant Rule: Color Focus). I applaude the writer for thinking outside the box and offering what many will see as lacking from the standard magic rule of D&D.
I would like to jump the gun here and suggest to the writer to go that step further and, if she chooses to do a Part 2 to this publication (PLEASE), release an additional variant rule covering a Magic and Mana System using the D&D spells but more along the lines of the M:tg CCG Mana System .... something to think about.
The writer has presented a great section within dealing with creatures and their affiliation with the 5 color elements recognised within the CCG game. Her breakdown of what creatures belong where, as well as a sample of new creatures is very well done. Seeing as she is also the famed author of the Critter Compendium, including those creatures in with a Part 2 would provide a HUGE additional amount of creatures to rely upon when Ravnica is released.
All-in-all; a fantastic piece of writing, and an author I'll be following more closely once Ravnica is released!!!