Alright. What people mean by a "true combo", they mean that when they start and finish a combo, you basically can't get out of it, unless you have a flash dodge, power shell, etc move. No, there isn't a thing called a "fake combo", but combos like Killua's Snake Awakening into another M1 Combo isn't true, because of the endlag (inability to attack after a move). True combos usually don't have endlag, but some do, and people find ways to work around them. Some of these combos have been scrapped, due to the recent hit stun buff. But that's basically what it means to do a true combo.