Ultimate Marvel vs. Capcom 3 has some of the best looking, longest but also difficult to pull off combos in fighting games. Vergil's combos are a good example of this - the timing of your inputs must be spot on for things to work.
Many of Vergil's combos utilise his "Round Trip" as a juggle mid combo, which is executed by holding any attack button for 1.5 seconds and releasing the button. Timing the release of the button for the "Round Trip" mid combo is critical - releasing too early or too late will cause the combo to drop.
After a Rising Sun (DP+L) with Trick ending (followed by H), Vergil is able to superjump and follow up with an air combo. This is also actually very difficult to time.
Fnially, Vergil can also juggle mid combo with a c.H into the Spiral Swords super. Again, doing the c.H too early will cause the attack to miss the opponent, while doing the c.H too late will cause the opponent to drop to the floor before it hits!
Have a look at an example of a Vergil combo which uses 5 bars of meter, one of which is a DHC. This combo is performed on a KeyCade KKL by BoAngel: