The realm as a whole has been forcefully isolated from contact with other realms, which has removed any danger of exterior threats, but has also removed any benefits such as trade and exchange of ideas. The two groups of people (the worshipers of Shimmer and Shine) are also isolated from each other, preventing any disputes that might arise between them but also creating prejudice, and preventing free trade and exchange of ideas.
The nurture of the realm's now deceased benefactor (Sharza-Zara) has solved the immediate problems but left the realm isolated from others and weak against them if contact is regained, and created a similar situation among it's once warring inhabitants.
The impracticality of the past is primarily the two groups impractical wars with each other, and the long-term impracticality of the spells Sharza-Zara cast.
The impracticality of the past has lead to weakness in the present. The realm lacks trade and such with others, and the lack of war has left them unable to defend themselves should a threat present itself.
With the dropping of the spell of peace, the temptation to take differences to war could be great. A great many other temptations could present themselves with the removal of the spell of isolation. This is a fairly inevitable future; if things continue uninterrupted, the followers of Shimmer will be tempted to take complete dominance; even with a 'good' ending, the removal of the great spells will present new temptations.
Sharza-Zara was a great mage who, most of the time used her power wisely. However, she let her love of the realm overcome her foresight, and her last three great spells, while they have kept the realm in check, have also prevented it's growth.
As a fortune draw, this usurper represents the wise and judicious applications of power, especially great power, but it can also mean the skillful application of lesser power to greater effect. Reversed, it means the use of power gone awry, due to lack of foresight as opposed to evil intent. Following it's name, it is especially meaningful when drawn while judging the effects of magic.