Fire Drake is a niche card. Unlike Holleas and Fanessa you can’t blindly summon Fire Drake with confidence you'll get good value. Not only does it need a lot of magic, which means less magic for other powerful cards, but Fire Drake is very fragile for its cost. If you are not careful, a lot of your magic can fade away, and with it, your chances of winning.
Its abilities are also of marginal, niche use, though in the right situation can be just what you need.
One of the strongest ranged options Phoenix elves have is Fire Drake working in tandem with Maldaria doing the "Maldaria cycle". Having two, 4-strength ranged units that become one, with only Fire Drake exposed, is a very powerful force and not easy to take at range. Against factions where Maldaria can struggle to push, this is a very solid option.
Remember that you can shoot through your own units, and while that may not seem ideal, it can allow you to use Fire Drake without exposing it and also to do a lot of damage through a single flank.
But Fire Drake's best use is against factions that swarm the board with units, then it's high cost becomes less of an issue and Fire Breath becomes especially powerful as it can effect several units with one attack.