I get your point. But what the developer meant by Mastery being necessary is kinda different. As you've not played the game yet (presumably), let me explain why his words don't necessarily contradict with 'free play style' as the game advertised.

Mastery is one of the three core mechanics of the game along with Destruction and Control. So to progress in the game mastery is important and actually indispensable in higher difficulties. However there are literally thousands of ways to use that 'Mastery' mechanic. In layman's term mastery isn't a particular type of magic or combat technique, but a core mechanic which you can use through any of the magic spells you craft.

In simple terms, suppose you're playing an action game and the game advertises that "you can create your own play style". That doesn't mean we should be able to finish that game without "firing any weapon" !! Right?

Because "firing weapon" might be a core mechanic in that action game. So that must be there. So a way to judge "play as you want" claim might be if there are different types of weapons and/or different types of bullets you can use depending on your choice; if you could play stealthily or go all guns blazing depending on your choice.

So yes you do need to use Mastery, specially on higher difficulties. What matters is if the game gives you freedom in using the way you want. In fact the game does :)

Those are good points, and now that I've played (and finished) the game, I can understand a bit what you mean. Yet I still found the Mastery mechanic to be a bit of a burden for playing any way you want. It's basically a necessity to apply the debuff to most enemies (and definitely bosses) before starting your regular attacks, and this becomes a chore that is repeated just about every time you see an enemy, which is always.

I may be veering more into personal opinion/preference now, but still, using Mastery still made me feel like my hands were tied. I couldn't just attack the boss with fire or whatever I wanted, I had to spend time stacking the debuff first just so I would do enough damage to matter.

So when all is said and done, I do still feel like the necessity of using Mastery cuts into the "create your own playstyle" promise of the game, but I understand what you mean about being able to experiment with *how* you use the various spells. It just ended up feeling like a pattern to me.

Yeah, I get you. 'Feeling like a pattern' as you said is one of the critical things that can be said about the game. There are a few other negatives that ultimately hindered the experience (regarding story and gameplay) but I won't get into that mostly because they were discussed more or less previously and also because as the developer said it wasn't their best game but their first, and when playing I thought they were sincere about making it a good, enjoyable and polished experience.

Just one point that I think should be worth noting if the developers are reading it, if you're playing in highest (Badass) difficulty, sigil level resets once they are unfocused which severely limits your playstyle. I know this was done to make the game tougher but a poor decision.By the time you get your 6th/7th/8th sigil the game progresses a lot, so why would the player have any motivation to change their sigil which they've already upgraded to 11 or 12 levels already and spent a lot of valuable (rare/epic) items and time(if you're a number-cruncher like me) to craft spells for them. Why would they get any motivation to start with a level 1 sigil when they know using and focusing on them means ruining all the time and effort that went into leveling them up and making spells for them.

My suggestion is that not only they should cancel this 'sigil level reset' mechamics in their future game/update, but your existing sigils (that you're not using currently but can activate from the vortex pool) or any new sigils you find should automatically be upgraded to the lowest level of the 3 sigils you're playing with now. That also implies cancelling the whole 'focusing sigil' mechanic.

If you want to ramp up the difficulty, sure, do it. Do it by making the AI smarter or through whatever other gameplay mechanics but not by imposing an artificial shackle to leveling up or anything that makes the player feel like all their previous efforts would be essentially negated.

Thank you :)