Ibn al-Khattab
Al-Saif seems to have been the trustee of Arab financiers, receiving money from them through some institution in Dagestan (likely the Makhachkala office of Benevolence International Foundation, a KSA-based Islamic charity, now banned) and distributing it to the Islamic insurgent forces across southern Russia. His predecessor in this role was Ibn al-Khattab, who was also a Saudi and was also killed in Dagestan.