Or Finwe?
I feel like the first stanza points to either Ingwe or Finwe, who travelled to Valinor and back, then went again (unlike Elwe), and stayed there.
The bulk of stanza 2 applies to both of them, assuming the 'backwards trip' is the Return. But who missed the 'slaughter cruel'? Is that Ingwe, who missed the Kinslaying by virtue of, y'know, not being anywhere near it - or Finwe, who missed it only by being the first to die?
Then there's the third stanza, which uses the same 'there' that previously applied to Valinor. It
could be that it's now referring to Middle-earth, and therefore means Ingwe, who let the Vanyar go to war without him. But it could also refer to Finwe, who gave up his chance to return to life in Valinor ('there') in favour of Miriel.
But 'the first among the first' means it's probably Ingwe; I just wanted to get my own guess in as well.
hS