Very basic BLM question

[chocopoko]

The only time it could get interrupted is if you move or you lose Umbral Ice, and thus lose Enochian. I doubt you are moving when you are attacking a dummy, so it would mean Umbral Ice is falling off, which means you are casting way too slow as it is really easy to fit the cast for T3 and B4 into the UI timer and have plenty of time spare.

using a keyboard and mouse would sometimes do this. coming from MOBA where skills are "QWEDFR" and 6 items slots use alt+"QWE ASD", I opted to put some skills on WASD with modifiers (ctrl, shift, alt) and it would sometimes interrupt my cast depending on when I let go of the modifier.