Listening to it several times while looking at the various versions of the lyrics, my current best guess is
Fire Emblem
Your spirit shall shine
Across the generations
Now and for all time
Fire Emblem
Heroes bringing us hope's light
Journey from distant worlds
To still the coming night
With sacred relics at your side -> With sacred relic at your side (I don't hear an 's', and I think it's referring to that one specific gun-shaped relic that the player insert character uses to summon new heroes)
See the champions fall from on high (I agree with Luxian's correction here, sounds closer and, continuing with my theory on the previous line it describes the effect of using said relic)
In this land where timeless heroes live
And their legends never die
Fire Emblem
Where heroes of the ages
With my desire your heart
Soon will start (?) anew (still not 100% sold on "start", but haven't heard any better suggestions. Makes it almost seem like the summoning is more of "resurrection" of dead heroes than simply pulling them from their timeline)
The end is really near our reach -> The end is nearly in our reach (the "within" correction proposed by Luxian here doesn't really fit with what I can make out from the recording, since I definitely hear a "-ly" in there. But "really near" is just such a casual wording that it doesn't fit with the tone of the rest of the lyrics, so I'd have a hard time accepting that they'd write that. "nearly in" sounds about as probable to me as "really near," but isn't quite as awkward)
Take up my fight 'cause I beseech (but I do agree with Luxian here; beseech makes more sense with both the rhyme scheme of the stanza and from the context of the game; the order of heroes may be being beseiged, but they are not calling on people to beseige; certainly not BOTH kingdoms)
Two kingdoms ravaged by senseless war
Bring us peace forever more
La lalalala lalala la lala lala lala
Lalala lala lala
Lalala lala lala
The strong, the weak, the brave, the meek:
All shall fight for the light we seek
Hear my voice, great hero, hear my plea
Come to me! Come set us free!
(Reprise of first two verses)