Well, for Zerkers like Herc and Lancelot they don't really need the Mad Enhancement, and in Herc's case it would make him even more OP than he already is.
The whole point of ME is that you trade sanity (and the abilities you have) for power.
If you could use your normal powers ANYWAY, then how would it even be a drawback. Use ME for power, turn it off and use your skills when you can.
But nobody does that, probably because you can't. I mean, Kariya could have had Lancelot not insane and out of control which would have helped him in a lot of situations.
Plus, it's weaved right into the summoning incantations, which kind of sounds like it's built into the way the Servant is going to operate for the duration of their summoning.
He never sleeps. He never dies.
Battle doesn't need a purpose; the battle is its own purpose. You don't ask why a plague spreads or a field burns. Don't ask why I fight.
I go with plot armor. And if she can't turn off mr in a later situation, that trumps retcon in my book.
Which, really, is the only book that matters for my argument.
Where couldn't she turn it off again, or are you taking Shirou never trying reinforcement on her (probably because he is unable to surpass Dragon Prana bursts with subpar reinforcement, and body reinforcement being super hard, and reinforcement of other bodies being close to impossible) as a confirmation.
[04:55] Lianru: i3uster is actuallly quite cute
What I said before is that I seem to remember her saying she'd TRY to turn off her MR after banging shirou.
Gen Urobuchi makes the best seires. HIs most recent, Psycho Pass, is pretty cool, though I think he's switched over to some kind of depressants.
I'd ask for quotes but I know you're too lazy for that :V
[04:55] Lianru: i3uster is actuallly quite cute
Hmm...I thought Ilya kept Berserker's ME on as a form of punishment.
That implies that you can turn it off, or at least have it off before you turn it on.