The language of the two are irrelevant to one another as it relates to the War Caster feat. In TS the spell must be incapable of affecting another creature at the level it is being cast. War Caster only restricts that the target be the one who provoked the AOO. As such by clear reading of the feat scorching ray could be used as could EB. The clear reading of those, in the spell descriptions, states that while they have multiple beams that could be directed at 1 or more creatures, with each beam doing X damage. In the case of the War Caster feat the text states this spell must target only that creature as opposed to “can only be able to target…” as twin spell states (paraphrased) The abilities of TS and WC do not overlap under this circumstance. Because the spell descriptions say that the option of who or how many targets each has is left to the player then EB and Scorching Ray would apply provided all beams were targeted at the creature that provoked the AOO. Furthermore, in case of EB or SR to put into the context of the limitations for twin spell they could in theory (if allowed to be twinned) target 6-10 creatures. As a single casting produces the multiple beams. Therefore, given the RAW in the case of War Caster provided the only target is the creature that provoked the AOO these spells that have multiple beams can be used. You could use spells that have multiple targets if upcast as well just choose not to affect other targets, but why? It doesn’t increase the save DC as they are static at 8+PB+spell casting modifier for each target, so to upcast it there is no benefit you just burn a higher level spell slot. If all you have is a higher spell slot maybe pick a different spell or cantrip at least then it doesn’t cost you a resource. In this case of a Druid just smack them with your shilealeah if you don’t have another spell. Then of course you can always forgo the AOO so as to conserve your resources. Just do a quick cost benefit analysis.
The language of the two are irrelevant to one another as it relates to the War Caster feat. In TS the spell must be incapable of affecting another creature at the level it is being cast. War Caster only restricts that the target be the one who provoked the AOO. As such by clear reading of the feat scorching ray could be used as could EB. The clear reading of those, in the spell descriptions, states that while they have multiple beams that could be directed at 1 or more creatures, with each beam doing X damage. In the case of the War Caster feat the text states this spell must target only that creature as opposed to “can only be able to target…” as twin spell states (paraphrased) The abilities of TS and WC do not overlap under this circumstance. Because the spell descriptions say that the option of who or how many targets each has is left to the player then EB and Scorching Ray would apply provided all beams were targeted at the creature that provoked the AOO. Furthermore, in case of EB or SR to put into the context of the limitations for twin spell they could in theory (if allowed to be twinned) target 6-10 creatures. As a single casting produces the multiple beams. Therefore, given the RAW in the case of War Caster provided the only target is the creature that provoked the AOO these spells that have multiple beams can be used. You could use spells that have multiple targets if upcast as well just choose not to affect other targets, but why? It doesn’t increase the save DC as they are static at 8+PB+spell casting modifier for each target, so to upcast it there is no benefit you just burn a higher level spell slot. If all you have is a higher spell slot maybe pick a different spell or cantrip at least then it doesn’t cost you a resource. In this case of a Druid just smack them with your shilealeah if you don’t have another spell. Then of course you can always forgo the AOO so as to conserve your resources. Just do a quick cost benefit analysis.