First off, don’t burn your 1st copy of any gold servant. We’ll get a free RP later on with Summer 2 rerun if you already bought the Medb costume else it’ll be on the Christmas 3 rerun with 5 RP if you already have an NP5 Santera. So CL or ML can wait for their boosts are quite negligible. They only save you like one run in a span of multiples, for ML especially. Forgot the full calculation but someone who remembers might say it eventually.
Secondly, d’Eon. As much as I love Lizzy more than d’Eon. The latter in my opinion has the slight edge for a 3 turn taunt is hard to pass-up on. Sure it may be way more niche than a waifu buffer, a whopping 60% might I add, but the utility of having a multi turn taunt can really make the difference between surviving or not.
Edit: Forgot to mention that during the LB story having VR Mash in your party grants 20% bond points for the entire party so even more of a reason to put CL on hold.