There is one final way you can level as an Elyos from 25 - 27 and that is by questing. Granted there aren't enough non-repeatable quests to level you fully from 25 - 27 but it will take away from the grind. You can get quests east of Teminon Landing at the blue circle on my map.
Below are the three quests you can get here to start. There is no specific order you should do them in.
Kill 7 Mind Reapers. The Mind Reapers can be found a little bit further in on the Island. The Mind Reapers can most commonly be found a bit off the ground flying around up in the air. So if you're confused why you're not seeing them, look up!
Collect 5 Green Minerals. For this quest you will need to collect 5 Green Minerals from the golems on the island. You can find the Golems around any of the Crystals or torn up landscape. They will be burrowed under the ground, as seen in the picture above.
Kill an Undead Destroyer and loot an Ancient Ring. The Undead Destroyers can be found just northeast of the quest givers. It may take a few in order to get the Ring.
After you complete the quests you will want to return to the NPC's and turn in all 3 quests. You will now be able to accept a Repeatable Quest called "Immortal Soul". This quest is a repeatable quest to kill the Immortal Ghost NPC's just east of you. Below is a video of where to go and me doing this quest.
You can grind this quest out until level 27, if you get bored you can switch it up with any of the other 25 - 27 areas.