Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Breathe Flame — Klauth's Will deals X damage to each creature without flying.
• Smash Relics — Destroy up to X target artifacts and/or enchantments.
(23/07/2021)
Whether or not you control a commander is determined only once, as you choose the modes for this spell. If you somehow lose control of that commander before you finish casting the spell (perhaps because you sacrifice it to activate a mana ability), it won't change the number of modes chosen.
(23/07/2021)
The commander you control doesn't have to be your commander.
(23/07/2021)
Once you've announced that you're casting Klauth's Will, players can't take any actions until you've finished doing so. Notably, opponents can't try to remove your commander to change how many modes you may choose.
