That second combo sounds like the bortk build combo. Literally no point in using that combo unless ur not gonna kill ur target in the first 2 seconds, and if you are using ult on a target you cant kill in the first 2 seconds then ur making a mistake right out of the gate.
Run Lethal Tempo, presence of mind, alacrity, the execution rune
Then run domination and take the ult cd reduction and any other rune in the domination tree.
warrior into duskblade into situational items.
Ur ult combo should just be r q e while ur in ult, time ur spellshield so that you block either the most damaging ability or a cc ability (which can be hard, VERY hard against champions that cast their entire kit at once like malph).
Maybe against champions like kai or vayne or anything that can move perpendicular to you really fast you MIGHT want to save q, and instead open with an E chilling smite so that you 100% hit ur q, but you would probably die since champions that you would do that to are cheesy 1 shot bots with every mechanic in their kit.