The battle against demons, particularly those well established in their goals and ways, having the resources they do is no quest for the most minor heroes. Many arcs of the previous story, especially dabbling in true dragons, fighting off the unliving hordes, or banishing demons, is the sort of thing you see in early middle levels of most Dungeons and Dragons characters and where most powerful classes have at last come into maturity; your wizards, your psions, your clerics, and so forth, or where prestige classes have gained traction. The place where your powerful agents begin to take interest and active intervention - angels, as reference.
While in a written roleplay there really is a lot more flexibility in the matter, the subject sort of requires some characters who are much more than common adventurers. Not everyone needs to be, but many characters are based on the principal of fatigue, as it is a staple of the genre; there are very few archetypes who can go on indefinitely, and those that do tend to be specialized in a singular role. Transitioning slightly...
Sakaala is an old, disabled monster - that alone makes her scary, in both the positive and negative lights; there's no doubt she's an actual monster, but at the same time misconceptions take time to mend and it certainly does not help that she's a sorceress. As a combatant she neither has the endurance or physicality to go on for an extended period beyond being determined and uncannily proficient with a sword. When the magic is depleted, it is gone.
Hills is not only a tiny halfling, but not exactly physically apt. Psychokinetically throwing daggers or teleporting can readily keep her out of reach - thus most dangers - but anything that decides it is not fond of a small psychic could put immense hurt on her with magic, its own psionics, or mundane ranged weapons. I need not even mention that the rogue's life alone is often short lived for a myriad of reasons.
Diagorides might be "the brute", but in a world of monsters and magic, superhuman strength and stamina through trial, training and endurance is certainly not out of place. Swords and spells undoubtedly still harm him, particularly given his method of combat, but at the end of the day if he so much lays a hand on something, it is likely to be taken down or subdued in brief.
In the end my point comes down to this; the fantasy genre is classically unbalanced.
A roleplay affords the characters, by virtue of their players, to overcome their limitations dynamically rather than mechanically or in a predetermined outcome. Emil, just because of his youth and comparative inexperience, does not inherently make him the weakest of characters - if anything he in fact has the most to gain within the world's lore based on the company he's keeping. It should also be noted that the vast majority of these characters are seasoned - most are well over forty.
Or so says my opinion on these matters.