i never knew Merle Ambrose had a tower in Avalon. i am not that level yet but i have been to Avalon. i do not now how to defeat Lady M. i guess you could just invite your online friends to help you.
Ghost Avalon is a place you have to have the quest to go in. If you're in it and you are starting to die it's over. You need to stand on the thing to go in. Period. No one can teleport to you.
How do you beat Morganthe in Merle Ambrose tower in Avalon.
Well, I haven't gotten into Avalon yet, but I'm close. I think you should load up on ice dispels and stun blocks so that she can't mammoth you twice a round or whatever her pattern is until she decides to change it and stun you. Or you can always use conviction. I know that there are no shields or spells above rank 4 aloud while you're in battle with Young Morganthe. If you have more than something like 4-7 pips, (includes power pip value), then she will mana burn you, so make sure you avoid that! Another thing, wear a lot of clothes with a ton of death and ice resist! I wouldn't think too much about critical rating because she usually blocks it. I would get a high enough block rating though because she criticals on most of her hits. Hope this helps.
Is that the next area after I manage to get the four light essences for Sir Patrick in the Night Garden?
It seemed like I cruised through the Catacombs, rescuing the Knight, and being led by him to restore the last Shrine near Artorius' tomb, since the Lady of the Lake could not help me any further (funny how she showed up with the cell door laying on the floor, before I had the chance to unlock it).
I have helped others that have found their way into Azteca, when they were battling the Lanterns in the Night Garden, so I have no idea what will come up next.
Timothy Pearlflower, Level 80 Archmage, battling Lanterns to gain four for Sir Patrick in the Night Garden
How do you beat Morganthe in Merle Ambrose tower in Avalon.
You are gonna need LOTS AND LOTS OF PATIENCE. There are a minimum of four fights, with Sir Mallory being last in Ghost Avalon, but you are gonna need all of your potion flasks for this one.
You are gonna be fighting as Gamma the Owl, Merle Ambrose's Pet, and when you fight in Ghost Avalon, you will learn how and why Merle doesn't trust anyone else as an assistant, since some back history will be learned that Morganthe sought to copy the Forbidden Spells (the ones from Zafaria), so that she could be as powerful as Ambrose.
DO NOT use any sort of shield on yourself, because Morganthe will attack with Mammoth at least twice, if not random on two, AND as long as no one comes in with you, you can quickly get back in the game (just make sure you avoid the Unsung Knight at the bottom of the stairs).
And don't stress out too much, because she can be beat, just make sure your team of four remains with you, cause it was interesting with three.
Timothy Pearlflower (Ice Archmage, Level 83) bouncing between Avalon, Pet Pavilion and The Hall of Plumage in Azteca.
How do you beat Morganthe in Merle Ambrose tower in Avalon.
I print out the guides, (I copy and paste to a word document - the important steps needed), that is shown in a post here at Wizard101Central.com and it actually went quite smoothly once we all got on the same page with the cheats.
We did prep decks before entering and had 2 set up - one for the mob fights with a few cards for quick defeats of them and one for her, this was easier then altering deck in between. We always win decks along the way so we keep 2 in back pack all the time. Of course I spent so much time getting everyone else going I forgot to switch from Boss deck to mob on first fight to I fled and came back with the right one equipped, lol. Mark just outside where you enter is all I can say.
There were 3 of us, 3rd person was more along for the ride than fighting and we each bought several TC of Melt to stop that annoy elephant stampede, altho they do cost you 2 pips to cast it was well worth the bother and we took turns putting them out so no one wizards pips were dry and she was always covered with them.
I also printed out the Pendragon one since that was next. We had a Death wizard run sun spot for both events and I being life did damage and health and second spot, 3rd person was also Life but has never played a support role so has not idea how to.
We later repeated it and replaced the 3rd person with her storm wizard and it was a disaster, she just couldn't seem to get her act together - forgot where to buy melts, forgot to load them in her deck and so on. What ya going to do it's mom We did get it done but was twice a long as first run.
As with all difficult battles wizard101central.com is usually the best bet to get it done. We are quite lucky to have this reference for all things Wizard101.
) 
We did get it done but was twice a long as first run.