Havn't decided yet on all of them, though my one lesser should be the charm one if I want to qualify for fiend of corruption at lvl 10 since I won't get any new invocations known at lvl 9 (lvl 7 warlock).<br/><br/>For least invocations maybe eldritch spear for the reach, baleful utterance since it has a lot of utility and then perhaps darkness for more stealth.