Slash is the preferred choice for this raid, even though Elafikeras is only slightly weak to it, but has decent resistance to other types. Thankfully, there are plenty of options available, and with a lowered Missile resist (compared to JP version), missile attackers are also somewhat viable, especially if they're Wind element.
Jeume is potentially strong enough to solo the raid since she has good damage and the self-sustain, but she will still need AP generating TMR like Illusory Bell or Emberlight Mantle. She can also boost the team's damage since she can reduce single target resistance and AGI, which will help with chaining or reaching the damage cap per hit more easily.
2B or Luartha (Winter) (with Soldier sub job) works quite well here as well if you happen to have them.
Alternatively, you can use Lu'Cia as the main damage dealer since she's the other "Large" unit raid boost and Tetra esper boosts Wind and Missile attack.
Both Sosha and Corwell can work with either Jeume or Lu'Cia since they both have Slash and/or Missile attacks to help with attack type and element chaining.
The next best options are either Light or Ice slash teams since Lucio and Rafale are free units that are also part of the raid bonus. Ice having slightly more advantage since Rafale can reach level 120 and Fenrir has both Slash ATK+ and Esper killer nodes, but you won't be able to pick all of them up.
Light with Lucio and Elsirelle is great for chaining since they both have a 3 hit attack. You'll have a much easier time if you also have a powerful limited-time unit like Starlight Elena or Kilphe (Summer).
Ice with units like Rafale and Lasswell don't have multi-hit attacks, but they can hit very hard since they can already reduce area and ice attack resistance and DEF down. Pair them with other strong Ice units you might have, like Gilgamesh, Velric, or Auron.
Elafikeras Stats & Resistances
Max Level Stats
CT Change Nullified, Accuracy Up, HP Debuff Res+999%.