The three worst spells in the spiral are: medusa because of the 2 round stun, earthquake (also ) because it takes away all of your blade and shields, and worst of all, sirens because they do pretty good damage to everyone, take away some blades, and put a -50% accuracy on everyone.
I have to add that I also find efreet right before you're about to use a spell, tower shields, legion shields, and the dreaded virulent plague very irritating as well.
This week's nominee for most annoying spell ever, has got to be mana burn. Lord of Winter is up there in second place, but at least requires they spend some pips before they steal yours.
I have NEVER been so disgusted that I fled a battle at almost full health before last night. Double balance opponents, elemental shields out, spamming tandem mana burns and my 9-pip attack disappeared. Entirely. Then weakness spam when they somehow know I have decided to scald or rain instead.
Weakness by far the most tedious spell in existence, In PVE, the enemies like to use it right before I attack and it keeps them alive to give me a "parting gift" It's especially bad if that's the only attack in your hand at the moment and you have to use ANOTHER TURN to discard every card and pass or shield just to finally get another spell to attack with
What is the most annoying spells enemies have casted on you in Dragonspyre? Mine is the fire meteor!
Tower shield, Heck Hound (they're only cast by non-fire so it's kind of annoying), Firezilla, Weakness, Colossus(Fire) and elemental shield. Keeps them alive from my Immolate or Helephant. =/
I agree completely; all of the bosses in DS and MB seem to love spamming weakness traps, and I sometimes end up with more on me than I could ever hope to get rid of in one fight.
Laura Shadowsong, Legendary Balance
I have to agree weakness is an annoying spell, the monsters just love putting it on me , more then i can get rid of and it really bugs me. Other spells that are really annoying are tower shield and absorb.
Earthquake... Especially in Azteca when you need all those blades to defeat the bosses. Also Sirens take to blades and swap it for a -50 accuracy (o my). I love earthquake such a huge advantage when you cast it :P
it is not weakness for 
people
pets using spritley (spelling) takes so long to finish a battle
