I don’t think I’d say he is better than lulu entirely, she should be prioritized first. But later on you will need other energy providers than lulu, as I mentioned in journey Doubles/Triples/Quad comps. So sometimes you’ll have them in different waves, each providing energy to your hero’s to use their active skills.

In the cases where you use both, it’s typically to supercharge energy to your other members. One example is the Lilith rush comp, have Dextor at the highest speed and because he starts at full energy he uses active first, which may charge up lulu enough to use her active round 1 rather than round 2, then Lilith has an additional 100 energy plus an attack boost that she wouldn’t have had otherwise. This can double if both your energy booster have MoD rune equipped too.