how do you beat him and no i don't have the gladius

heres what i did. first you enchant your sword and slash him and then his little anchant will show up so go and slash it. then youll play as the ghoust of the other characters just do the same thing you did with alex. after his mini anchant is dead. then just run around him in circles and when he stops slash him with your sword.repeat that for awhile and youll win. make sure you avoid his magic attacks

It really helps to have the always enchanted sword that you can get in the level befor.

First I had the permanately enchanted sword you get with Micheal. Then you just hit him and run and then hit the mini ancient (depends on what rune you picked at the very beginning, for me it was a blue jellyfish) and just repeat that, eventally you will start becoming the other people you had in the chapters (all except Micheal because he is still alive(slipped you the package with rune and sword) and eventually the mini ancient will break, now just whack the guy till he starts transporting and use this opurtunity to do a quick heal spell and just keep repeating that (making sure if you do a heal spell he is not casting a spell or near you) and he will eventually die. Now your done! all that is left is clicking a rune as your gandpa and then a cutscene!