I don't think Leliana has any way to resist the
celerity +
time stop combo, so Elminster will always open the fight with an average of 6 other spells. Once this combo starts, all he needs is to walk near Liliana, cast
prismatic sphere +
antimagic field (prismatic sphere cannot be dispelled or negated as RAW except by 7 specifics spells to be casted in succession, which Liliana is now unable to cast, if she had even learn them;
antimagic field can be negated only by deities) and proceed to stab Liliana to death once
time stop is ended with his superior melee skills.
And again, 3 months of preparations would be overkill for Elminster: he may research the names and summons all the demons within Leliana, compromising her power. Heck, he may very well summon Leliana herself within a
circle of protection against evil, which will leave Leliana entirely powerless.
Even without all this crazy stuff, a spell resistence spell cast by Elminster would give him 40 Spell Resistence, which by D&D mechanics most entities (at least in D&D) below Low 2-C would find extremely hard to surpass, affecting Elminster only with 1 spell every 20 they cast, while those on par with Elminster magical prowess (aka Spellcaster Level, which in Elmister case is significantly higher than many D&D gods) will affect him on average with 1 spell out of 2.
Other things Elminster can do even without much preparation:
- permanently destroy The Chain Veil via
disjunctio.
- permanently bind Leiana with
bind,
sequester,
imprisonment or
temporal stasis spells.
- permanently turn Leliana into a statue incapable of acting and use spells via
flesh into stone. Proceed to disintegrate said statue.
- close Leliana into a
prismatic sphere, negate all gate, summoning, plane shifting, teleportation and similar abilities within the sphere via
dimensional lock, and leave Leliana contend with multiple spells like
incendiary cloud and summoned creatures (summoned before casting
dimensional lock ofc).
- use
polymorph any object on Leliana to turn her into something with low mental ability scores to negate her spellcasting abilities. He can, for example, polymorph her into a steak and have lunch.
- Elminster has a spell to protect himself against anything, even if he doesn't know, or hasn't prepared, a particular spell (possibly because isn't a spell normally available to wizards) he can still copy it with
limited wish or
wish. Most notably,
mind blank and
death ward spells would guard him against almost everything Leliana would normally use.
- In the event Leliana can somehow kill him,
Elminster's evasio will bring him back at least a second time, even from beyond death, Even should Leliana eat his soul.
All of the above only considering the core spells, I can't even list all possible combinations Elminster ha at his disposal (like
prismatic sphere +
dimensional lock +
maw of chaos and God knows whatever else). If anyone is interested to know why high-level D&D wizards have an hax for every contingency, you can
read this .
