The Captain

"To survive in this galaxy you need a wand in one hand and a gun in the other."
On a little-known planet Archmage Varic Vallenar casts a grand spell to empower himself with the magical abilities of his alternate selves. The ritual works too well granting Varic not only the magic but also the memories from six lives.
Including their gruesome deaths.
Now Varic has power greater than any wizard in galactic history but he knows that won't be enough. The enemies he faced in those alternate lives were apocalyptic in scale. Terrors of technology and magic. Nothing that he or anyone can defeat.
Sun-eating extra-dimensional insects shadowy secret organizations genetically enhanced alien super-soldiers ruthless mega-corporations and hordes of cyborg undead all lurk in the darkest corners of the galaxy and Varic knows that any of them can become a world-ending threat at any moment.
All these are beyond any wizard no matter how many spells he's mastered or how many interstellar warships he's rallied to his cause. Hopeless Varic finds himself trying to preserve what little he can from the coming doom.
Until he hears rumors of a mythical starship an invincible vessel of heroes made to do battle against galactic threats.
A ship called The Last Horizon.