Hi Joey ! I'm not familiar with the plants you mention but I would probably ask at the garden center you are buying them at what the problem is! It's so frustrating to try plants more than once and fail .

Hi Joey, Colocasias love lots of water and prefer to stay moist most of the time. They also do much better with shade or filtered sun (like through tree foliage). Any midday sun would be too intense for it. I am in Florida and have our Mojito in the ground in an area that gets watered quite a bit. If your pot is a terracotta pot, those dry out quickly. You could plant it in a regular plastic pot and put it inside the terracotta if you like that look. Good luck! Mojito is a resilient plant and I'm sure it will do well for you once you cater to its preferences!