I'm assuming you're referring to score runs here, in which case I'm going to say
MoF's Faith maintenance > IN's coordinated focus/unfocusing > SA's ubergrazing > UFO's UFO chaining > > PCB's border maintenance
SA's supergrazing is much easier than what most people think; however it
is character dependent. Then you have to survive bosses like Orin without dying a lot and / or bomb spamming.
MoF's Faith system is
ridiculously difficult to control, particularly on Stage 4. In addition to
near perfect timing, you also need to pull
100% deathbomb rate (which I still fail sometimes, even if it's a scoring bomb and I
know I'm going to bomb). You also need to
moderate bomb usage on the stages, or you'll end up suffering from cumulative error. The only Spell Cards you're allowed to bomb away without destroying your score by a "major" amount are:
"Kappa"MoF S3 SC4 series,
"Illusionary Dominanace" /
"Peerless Wind God"MoF S4 SC3 or "Cork"MoF S4 SC4 series,
"Preparation"MoF S5 SC4 or "Miracle"MoF S5 SC5 series,
"Sacrifice" /
"Mystery"MoF S6 SC3 series (to some degree; you're losing out on about 30-40mil total if you do bomb this on a good run), and
"MoF" /
"VoWG"MoF S6 SC5.
You bomb the
"Bad Luck"MoF S2 SC1 series for score.
IN's time point system is probably the easiest; basically going through without dying / deathbombing without destroying a ridiculous amount of familiars on the stages seems to give you enough time points. Bosses
are a problem though.
Finally, UFO. I guess if you time it right, then there
should be no problem. Though, that's saying from only playing the Trial :V
If you're just going for a clear, then I'll say MoF. Scoring; IN.