tension and lesion.
Words ending with "ition":AbolitionAcquisitionAdditionAmbitionAmmunitionApparitionAuditionCoalitionCompetitionCompositionConditionContritionDefinitionDemolitionDispositionEditionExhibitionExpeditionExtraditionIgnitionImpositionInhibitionInquisitionIntuitionMalnutritionOppositionPartitionPetitionPositionPrepositionProhibitionPropositionRecognitionRenditionRepetitionRequisitionSuperstitionTraditionTransitionTuitionWords ending with "sion":AbrasionAdmissionAggressionAllusionAscensionCessionCollisionCommissionCompassionCompressionCompulsionConcessionConclusionConcussionConfessionConfusionConversionConvulsionCorrosionDecisionDiffusionDimensionDiscussionDiversionDivisionEnvisionExclusionExcursionExplosionExpressionIllusionImplosionIncisionInvasionMansionObsessionSeclusionSessionTensionVision
tension
sionist, sionism
I only know one word that starts with de- and endsin -sion is decision.
Some examples of words with the suffix -sion are discussion, decision, and expression.
Words that end in -tion usually come from Latin, while words that end in -sion usually come from Latin or French. There isn't a strict rule, but -tion is more common and originates from Latin verbs ending in -tio, while -sion more often comes from Latin or French words ending in -sio or -sion.
Fusion Fission
Expand\expandsion
Sion Shankel goes by Sion Shankel.
Oddly enough the word is spelled the same in Spanish as it is in English. Only the pronunciation is diffferent. deh-see-siON
The spelling of "question" comes from its Latin origin "quaestio," where the "t" is used instead of "s" to keep the sounds consistent with the root word. This change in spelling is a common pattern seen in Latin-rooted words in English.
permission, decision, emission, mission, discussion, omission, illusion