How hard is irellia.

So I see that irellia counters the big reworks like maokoi and Zac. I won't have to worry about sejuani since she's only jg. Iher abilities don't seem to complicated like her q is a dash. Her w is similar to Yi. Her e us a stun and it works similar to renekton. Her ult just shoots 4 blades with a relatively big hotbox presumably. Does she have a low skill floor.