In da2 there is, Idunna, a blood mage sex worker trapping templars with her mind manipulation blood magic. She can make Hawke try to slice their own throat, and Hawke can ask for help from Anders or Merrill. I assume both of them use Dispell Magic for this.
And it's like, why didn't the templars use their own version? Isn't that their whole deal?
But as you see, Dispel Magic is a basic spell from the Spirit tree that just requires level 3, while Cleanse needs level 8. So you can imagine the templars could be underleveled for Idunna, also Hawke usually comes with a group and most likely the templars went alone.
Mage Hawke can also stop the spell by their own (if i remember correctly) BUT rogue/warrior can just stop the spell by their own willpower, no magic skill required. And if we go a lil bit back to DAO, all the templars are being tricked by demons, including Alistair, while the main character, Sten and Morrigan don't fall for it. Every templar in therinfal falls for an envy demons trick but we know Krem and the chargers success defeating it.
So this is my theory: Templar training and lyrium might make you good at fighting basic magic, but it makes you wayyyy weaker to blood magic and demon influence. I don't think this is caused by lyrium, cause you can play templar specialization no problem, but no origin is templar based. Of course this is Main Character syndrome, but we are looking into In Universe reasons here, imo this is cause the chantry teaches templars to be obedient To Them Only and never doubt, wich is just making them easy prey to anything that activates their "obey" button in their brain that is supposed to work only for the chantry, but really anyone else could use it.
