I feel like the Devour glyph doesn't really live up to its name. You'd think it'd be good as a snowball that picks up damage the more you fail to stop it. But it just takes longer to stop.
I'd rather see Devour go "if it wins, it gains 10% damage instead", or something else along those lines. This way, more dangerous opponents who might use it prompt you to be prepared with a cleanse or defense rune to break it before it becomes a nuke. To compensate, it may be possible for a glyph to have "final" ratios that affect how much power they can gain (after materials) so getting that giant unstoppable nuke is harder to obtain.