I use Thorne in combination with Frida and Vela. I usually kill (or at least severely weaken) two or three heroes once they fire their specials.
Thorne is a worse version of a Master Lepus with bad attack stat.
But at least he can live to fire once…
My issue with Thorne is that there is absolutely no reason to level him. He will not improve titans, he will not improve tornaments and he’ll only slightly improve wars. He has no synergies or buffs/debuffs, meaning his sole purpose is damage - and he’s not that good at it. I’d rather level up a third Kiril than level Thorne.
And he’s boring. I know that there are arguments that Glenda sucks. But at least she (Like Zocc and Bai) bring some thinking, timing and fun to attacking. Thorne is just … boring.
Depending on your roster, he can improve many areas of your game.
I think he’s worth leveling if he is one of your first legendary heroes.
One of the best S1 tanks, will probably serve newer players as raid tank for a long time. Very good in very fast tournaments unless your loaded.
Of course not comparable to the likes of Vela and Master Lepus.