I like "soever" because you can do tmeses with that a bit like with Latin cumque. In an archaic style, that is.
Latin example:
Vero, et a peritissimis sunt istis de rebus et responsa et scripta multa, et ego in hoc omni sermone nostro, quod ad cumque (= ad quodcumque) legis genus me disputatio nostra deduxerit, tractabo quoad potero eius ipsius generis ius civile nostrum, sed ita locus ut ipse notus sit, ex quo ducatur quaeque pars iuris, ut non difficile sit, qui modo ingenio possit moveri, quaecumque nova causa consultatiove acciderit, eius tenere ius, quom scias a quo sit capite repetendum. (Cicero, De Legibus II)
English example:
[1] The Revelation of Jesus Christ, which God gave unto him, to make known to his servants the things which must shortly come to pass: and signified, sending by his angel to his servant John, [2] Who hath given testimony to the word of God, and the testimony of Jesus Christ, what things soever (= whatsoever things) he hath seen. (Douay-Rheims Bible, Rev. 1)