そこでおそらくこれは久しぶりに戻ってきた古代の神に違いないと考えた。

Sentence Analyzer

そこで おそらく これ 久しぶり 戻ってきた 古代 違いない 考えた

English Translation

So perhaps this was their ancient god returning after his long absence.

Furigana

そこでおそらくこれは(ひさ)しぶりに(もど)ってきた古代(こだい)(かみ)(ちが)いないと(かんが)えた。

Romanji

Sokode osoraku kore wa hisashiburi ni modottekita kodai no kami ni chigainai to kangaeta.

Words

其処で (そこで)
so; accordingly; now; then; thereupon; therefore
恐らく (おそらく)
perhaps; likely; probably; I dare say
此れ (これ)
this (indicating an item near the speaker, the action of the speaker, or the current topic); this person (usu. indicating someone in one's in-group); now; here; I (me); certainly
()
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
久しぶり (ひさしぶり)
a long time (since the last time); it's been a while (since I last saw, mailed, etc., you)
()
at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although
戻る (もどる)
to turn back (e.g. half-way); to return; to go back; to recover (e.g. something lost); to be returned; to rebound; to spring back
古代 (こだい)
ancient times
()
indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question
(かみ、かむ、かん)
god; deity; divinity; spirit; kami; incredible; fantastic; emperor of Japan; thunder
違い (ちがい)
difference; discrepancy
()
if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)
考える (かんがえる)
to think about; to take into consideration; to ponder; to reflect; to try to come at a conclusion; to think over (something); to intend; to decide (to do); to plan; to come up with; to devise; to scheme; to predict; to anticipate; to expect; to suspect; to doubt; to consider (somebody to be something); to look on

Kanji

Readings: キュウ、 ク、 ひさ.しい
Meanings: long time, old story
Readings: レイ、 もど.す、 もど.る
Meanings: re-, return, revert, resume, restore, go backwards
Readings: コ、 ふる.い、 ふる-、 -ふる.す
Meaning: old
Readings: ダイ、 タイ、 か.わる、 かわ.る、 かわ.り、 か.わり、 -がわ.り、 -が.わり、 か.える、 よ、 しろ
Meanings: substitute, change, convert, replace, period, age, counter for decades of ages, eras, etc., generation, charge, rate, fee
Readings: シン、 ジン、 かみ、 かん-、 こう-
Meanings: gods, mind, soul
Readings: イ、 ちが.う、 ちが.い、 ちが.える、 -ちが.える、 たが.う、 たが.える
Meanings: difference, differ
Readings: コウ、 かんが.える、 かんが.え
Meanings: consider, think over