The king is dead, and now four factions fight for the throne.
You are a member of the great House of Pierpont. The throne is yours... by right (objectively, in terms of the line of succession).
But not all of the other houses care, in fact, your enemies side with pretenders (coming up with lies that are unacceptable to you) and unfortunately for you, they've got the numbers. In fact, you are the THIRD LARGEST faction. Two factions individually outnumber you. Everyone is fighting everyone and there's additional politics to get the other neutral houses to enter and support various sides.
As a lord of Pierpont, you have some things going for you:
a massive force of mounted cavalry (many of the very finest knights in the realm)
a solid defensive position
relatively experienced commanders from the last big war
Unfortunately:
while you have some farmlands your food supply and access to important resources is vulnerable without further conquests.
you have a very bad reputation amongst the other lords (a lack of popularity) because you have in the past, very unwisely insulted many of the great houses
...
As it turns out, magic is a real thing. It's just that no one really knows how it works exactly. Some magic users can cast magical attacks in battle and cause objects to fly but some of the most powerful magic users can bless and curse entire armies (there are only a few of these people around now). One of the Great Witches has offered to bless your campaign in exchange for a high ranking position at your table after the war. The Great Witch has already demonstrated feats of magic to you.
If you take the deal, the Great Witch will bless your army and curse all of your enemies. The Witch tells you that this will greatly swing things in your favour and chances are good that your enemies will start dropping dead one after another until you take the throne, though victory is not guaranteed. However, you will have to pay for it through a mechanism of fate where you lose 1/3 of your remaining lifespan. You have no idea how many years that amounts to.
You're not sure you believe in this magic thing but many of your advisors tell you "Yes it is real, and you need it, we're outnumbered."
Now assuming only you have access to this magic thing (your enemies don't) and assuming you can't back out of the war (it's too late, you'll always be considered a threat to the claims of whoever took the throne), your options are clear:
1. Accept the Dark Magic deal. Offer up 1/3 of your life and continue to fight the war with a blessing on you and a curse on your enemies (but not being very sure how that works out or whether or not you'd really win).
2. Say no to the Dark Magic. Fight the war using normal strategy, politics, diplomacy, and military skills.
Please also factor in that the use of Dark Magic is a huge taboo and if you accept the help, your reputation amongst the other houses and the common people will further plummet due to the bad PR.
What do you do?
